CONTINUOUS IMPROVEMENT IN THE THEORY OF RESTRICTIONS:
The Theory of Constraints was first described by Eli Goldratt in the early 1980s and has been widely used in industry ever since. It is a set of thought processes that uses the logic of cause and effect to understand what is happening and thus find ways to improve. It is based on the simple fact that multitasking processes, of any scope, only move at the speed of the slowest pace. The way to speed up the process is to use a catalyst that is the slowest step and get it to work to the limit of its ability to speed up the entire process. The theory emphasizes the elusiveness, findings, and supports of the main limiting factor. In describing this theory these limiting factors are called constraints or "bottlenecks."
Of course the restrictions can be an individual, a team, a piece of a device or a local policy, or the absence of some tool or piece of some device.
theory-of-constraints-toc-theory-of-constraintsBanna precisely reminds us that the book LA META, by E. Goldratt, highlights the application of the Theory of Constraints (TOC - Theory of Constraints-), where the core idea is that in every company there is, at least, one restriction. If not, it would generate unlimited profits. Since the restrictions are factors that block the company from obtaining more profits, any management that aims at this objective must manage by focusing on the restrictions. The truth that TOC is a systemic methodology for managing and improving a company. In short, it is based on the following ideas:
The Goal of any for-profit company is to earn money on a sustained basis, that is, by meeting the needs of customers, employees, and shareholders. If you do not earn an unlimited amount, it is because something is preventing you: your restrictions.
Contrary to what it seems, in every company there are only a few restrictions that prevent you from making more money. Restriction is not synonymous with scarce resource. It is impossible to have an infinite amount of resources. Constraints, which prevent an organization from achieving its highest performance in relation to its Goal, are in general wrong decision criteria.
PRODUCTION: HOW TO IMPROVE WITH TOC:
The Theory of Constraints developed from its "Production Optimization Program". The starting point of all the analysis is that the goal is to make money, and to do so it is necessary to increase throughput; but as this is limited by bottlenecks, E. Goldratt concentrates his attention on them, giving rise to his "OPT" program that leads to "The Theory of Constraints". Producing to achieve a comprehensive use of installed capacity, leads the industrial plant in the opposite direction to the goal if these units cannot be sold. The reason within E. Goldratt's scheme is very simple: inventories rise, operating expenses rise, and throughput remains constant; exactly the opposite of what was defined as the goal. AND.Goldratt argues that everyone believes that a solution to this would be to have a balanced plant; understood by such, a plant where the capacity of each and every one of the resources is in exact accordance with the market demand.
It seems to be the ideal solution; Each resource generates costs for a capacity of 100 units, which are fully absorbed because each resource needs to manufacture 100 units, which is the market demand.
Based on this theoretical solution, companies try by all means to balance their industrial plants, trying to match the capacity of each of the resources with the market demand.
Assuming it is possible, the production capacity of productive resource one is reduced from 150 units to 100 units. In this way, operating expenses decrease and, supposedly, inventories and throughput remain constant.
But according to E. Goldratt all this constitutes a very serious error. Matching the capacity of each of the productive resources to market demand inexorably implies losing throughput and raising inventories.
The reasons given are the following: E. Goldratt distinguishes two phenomena called
DEPENDENT EVENTS - One event or series of events must take place before another can begin. To meet a demand of 100 previously it is necessary that the number two productive resource manufacture 100 units and before this, it is necessary that the number one productive resource do the same.
STATISTICAL FLUCTUATIONS: assuming that the dependent events are going to occur without any alteration is a utopia. There are fluctuations that affect the activity levels of the different productive resources, such as: quality of raw material, absenteeism of personnel, machine breakdown, power outage, lack of raw material and even decrease in demand.
The combination of these two phenomena generates an unavoidable mismatch when the plant is balanced, producing a loss of throughput and an increase in inventories.
It can be noted then that TOC is being applied successfully in many countries and in all aspects of business activity: Operations (goods and services), Supply Chain Management, Project Management, Decision Making, Marketing and Sales, Strategic Management and Human Resources.
There is no doubt that with the identification and proper management of restrictions, significant improvements are achieved in a short time.
As a process, TOC is structured in iterative steps focused on the constraint of the system.
2 types of restriction are identified:
Physical constraints that normally relate to the market, the manufacturing system, and the availability of raw materials.
Policy constraints that are normally behind the physical ones. For example; Rules, procedures, evaluation systems and concepts.
The sequence of the iterative improvement steps depends on the type of constraint being analyzed.
The improvement in TOC refers to the search for more “goal” of the system or company without violating the necessary conditions. To achieve the goal more quickly it is necessary to break with several paradigms. The most common are:
Operate the system as if it were made up of independent “links” rather than a chain.
Make decisions, including pricing, based on accounting cost, rather than on contribution to goal (Throughput). Requirements of a large quantity (oceans) of data when few relevant ones are needed. Copying solutions from other systems instead of developing your own solutions based on methodologies of logical "effect-cause-effect" relationships.
Continuity in the search for improvement requires a measurement system and a method that involves and encourages staff participation. To define the measurement system, it is necessary to define the set of goal indicators. At TOC, the goal of a business is to make money now and forever. The measurement of the goal will be carried out through the indicators; Throughput (T), Inventories (I), and Operating Expenses (GO). The method recommended by TOC is the Socratic, which encourages the participation of staff, the development of their own solutions, and teamwork. TOC favors the application of methodologies that involve the development of “know how”, instead of the use of external consultants.
SYSTEMATIC APPROACH TO OCD:
a) IDENTIFY THE SYSTEM RESTRICTIONS: a restriction is a variable that determines a course of action. There may be different types of restrictions, the most common being physical: machinery, raw materials, labor, etc.
b) EXPLOIT THE SYSTEM'S RESTRICTIONS: it implies looking for a way to obtain the highest possible production of the restriction.
c) SUBORDINATE EVERYTHING TO THE PREVIOUS RESTRICTION: the whole scheme must work at the rate set by the restriction (drum)
d) RAISE THE SYSTEM'S RESTRICTIONS: implies undertaking a program to improve the level of activity of the restriction. Eg outsource
e) IF A RESTRICTION IS ELIMINATED IN THE PREVIOUS STAGES, RETURN TO STEP a): to work permanently with the new restrictions that appear.
- The Goal of any for-profit company is to earn money on a sustained basis, that is, by meeting the needs of customers, employees, and shareholders. If you do not earn an unlimited amount, it is because something is preventing you: your restrictions. Contrary to what it seems, in every company there are only a few restrictions that prevent you from making more money. Restriction is not synonymous with a scarce resource. It is impossible to have an infinite amount of resources. Constraints, which prevent an organization from achieving its highest performance in relation to its Goal, are generally the wrong decision criteria. The only way to improve is to systematically identify and remove constraints. TOC proposes the following process to manage a company and focus improvement efforts:
THE DBR SYSTEM (DRUM, BUFFER, ROPE)
It is an iterative process, which we could describe in a simplified way as follows:
- Schedule product deliveries to customers using delivery dates Schedule capacity constraints considering delivery schedules and dispatch ropes Optimize capacity constraint schedules Schedule the launch of raw materials and components taking into account It counts the programs of the restraints and the internal and assembly ropes.
The details of the production scheduling process depend on each particular case and must be taken into account in case of a manual implementation. In the case of an implementation supported by commercial software based on TOC, it already takes into account the vast majority of the peculiarities of each production system.
It should be noted that the entire plant is not programmed, but only the minimum critical points that will ensure control of the system. This way of proceeding has several advantages, among them:
- Operations programming time is significantly reduced without losing control.
- The probability of reprogramming is minimized because the transmission of random fluctuations is minimized.
BASES OF THE DBR MODEL
In all plants there are some resources with restricted capacity. The DBR method recognizes that such restriction will dictate the production rate of the entire plant. The main resource with capacity restriction will be treated as "the drum" which is the one that will determine the production speed of the entire plant. You will also need to establish an inventory "buffer" against the limiting factor. This buffer will protect the throughput of the plant from any disturbance that occurs in the non-bottleneck factors. And finally, to ensure that inventory does not grow beyond the level dictated by the buffer, the rate at which materials are released to the plant must be limited. A "rope" must be tied from the bottleneck to the first operation;In other words, the speed at which materials are released to the plant will be governed by the speed at which the bottleneck is producing.
STAGES OF THE DBR MODEL
a) The first step will be to schedule the production of the bottleneck resource (CB) taking into account its limited capacity and the market demand that it is trying to meet
b) The second step will be to schedule the production of the remaining resources that are not CB
c) Programming subsequent operations to the CB is a simple task. Once a part is finished in a CB the next operation is scheduled. Each subsequent operation, including assembly, simply starts when the previous operation ends.
d) The complicated thing is to program the preceding operations and protect the CB from the disturbances that may occur in the previous resources.
e) On the assumption that most of the possible disturbances do not exceed two working days, a protection of three days in the time buffer will be more than enough to protect the throughput from the bottleneck.
f) The next step is to program, going back in time, starting from the bottleneck. The operation immediately preceding the CB will be scheduled to complete the necessary parts three days before they are scheduled to be used in the CB
g) Each of the preceding operations will be scheduled retrospectively in a similar manner so that all parts are available just in time for the next operation.
h) In this way, a program and a time buffer can be generated that satisfies all the requirements of the scheme. Any disturbance in the preceding operations, which can be overcome within the time buffer, does not affect the throughput of the plant.
i) It remains to define how the other part of the product that forms part of the final product through assembly is purchased (quantity and periodicity).
j) The important thing is to also generate a buffer stock of this part compared to the assembly operation that requires a part of the CB to form the final product. The purpose of this buffer will be to protect the assembly program against disturbances that may occur in supplies of parts that do not pass through the CB.
Although it is true and it is accepted that this part of the development is the most redeemable of all the contribution of E. Goldratt, we wonder if the application of a Just-in-Time scheme, in its modern and updated conception, does not fully respond to this programming model proposed by E. Goldratt. But for him it is not like that, and he even emphatically marks his difference with JIT by the existence of buffer stocks; This clearly demonstrates their lack of knowledge of the subject, as they participate in the widespread error that Just-in-Time is synonymous with zero stock.
SET THE “DRUM BEAT”
The first activity would be the identification of the CCRs.
The determination of the MPS of the plant, according to the rhythm of production established by the CCR's, is carried out as follows.
First, the program is defined to process the orders in the CCRs using their maximum capacity. This would consist of defining the production sequence, the production batch size, and the transfer batch.
If the CCR does not require set-ups, the production sequence must be based on the delivery date. The production lot size must be equal to the order size. The only variable to define is the size of the transfer lot. Small transfer batches result in a better material flow, with lower inventory levels, but greater handling.
If the CCR requires set-ups, it is necessary to determine the production lot sizes. Long set-up times lead to large production batches, which would strongly impact customer delivery times and inventory levels. The definition of the batch size is related to the production sequence, in case of looking for the same products to increase the batches to process.
The rest of the program (for non-CCR resources) is developed based on the previous one.
Determine the "Rope"
Rope's function is to communicate effectively throughout the plant the actions required to support the MPS.
Rope development should only consider relevant detailed information that is transmitted to specific and critical points in the production system, called schedule release points. In addition to the CCR's, these are:
Therefore, the focus on maximizing utilization and improvement programs should be geared towards bottleneck resources.
Making the most of and investing in non-bottleneck resources increases inventories and operating expenses without increasing Throughput.
Activating a resource refers to using it to process materials or products.
Using a resource means that it contributes favorably to generating more goal (T).
- The performance of the assembly stage depends on the rhythm established by RB.
- In case of over-activating RNB, the result would be the accumulation of inventory
in process prior to assembly.
- Therefore, the performance of RNB depends on that of RB.
- We concluded that T and how to operate RNB depend on RB.
IMPLEMENTATION OF THE THEORY OF RESTRICTIONS
Critical Chain Project Management (Theory of Constraints) provides the following benefits for your Project Organization:
| Projects will be completed more quickly. | ||
| Team morale and effectiveness will improve because they will be working in an environment that is comfortable with uncertainty and that avoids micro-management. | ||
| Project Managers, Resource Managers and Executives will have a simple, very effective macro level method for evaluating project performance and making resource decisions using a traffic light. | ||
| Executives will have an effective tool to make project decisions based on project priority and organizational capacity using project timing capabilities. |
To achieve the above benefits, you need to establish a total project environment that integrates both the elements of human behavior and methods into an effective operating unit. Project Scheduler 8 makes method implementation easy with its built-in Critical Chain functionality within the software. The human side requires that everyone from Senior Management to the Project Team understand and "buy" these concepts.
TYPES OF RESTRICTION:
Restriction is any element that limits the system in achieving its goal of generating money.
Every system or company has restrictions.
Market Restriction: The maximum demand for a product is limited by the market. Satisfying it depends on the ability of the system to cover the established success factors (price, speed of response, etc.).
Materials Restriction: Throughput is limited by the availability of materials in adequate quantity and quality. The lack of material in the short term is the result of poor programming, allocation or quality.
Capacity Restriction: It is the result of having equipment with capacity that does not satisfy the required demand of them.
Logistics Restriction: Inherent restriction in the production planning and control system. The decision rules and parameters established in this system can adversely affect the smooth flow of production.
Administrative Restriction: Strategies and policies defined by the company that limit the generation of Throughput. EOQando and encourage local optimization.
Behavior Restriction: Attitudes and behaviors of staff. The “busy all the time” attitude and the tendency to work easy.
THE IMPLEMENTATION PLAN:
Resources with Restricted Capacity (CCR's)
Deviation may be the result of not meeting the amount and / or timing of the flow.
A CCR may or may not be a Bottle Neck Resource.
A Bottleneck Resource incorporates the quantity element.
A CCR involves quantity and time. Focus on CCR's!
An RB can be a CCR because it is deficient in capacity.
The identification of CCRs that are not Bottlenecks can be done through a resource load analysis.
Approach to Synchronizing Production
The purpose is to meet Throughput expectations by efficiently managing inventory and operating expenses.
The TOC recommended approach to synchronizing production is the Drum-Buffer-Rope (DBR) system.
The application of the DBR system begins with the elaboration of the Master Production Program (MPS).
The MPS begins with the detailed programming of production in the CCRs. This establishes the bases for scheduling production on the floor and defining commitments with clients. The rhythm of production defined by the CCR's is called Drum (drum).
The inherent variability of the production system incorporates the need to establish slack factors in the resulting program. This slack would occur through incorporating in the process time a slack known as time buffer.
The final production scheduling is completed with the scheduling of material requirements and other resources that are not CCR's. This is done through a procedure known as Rope.
Profit companies have, above all, a social function which is: to create more and better sources of real work (creating value). That is, they must grow while maintaining the "win-win" of all parties involved in the "macro system" (company, region, state, country, world). However, in order to achieve and maintain this social function, companies need to generate added value and this is usually called profits.
Therefore, "The Goal" of companies is usually expressed in some relationship with the generation of profits. This GOAL is normally expressed as Effective Return on Investment (REI), which means: how much the money invested in the company yields above the normal cost of money (banks). If the company is on the stock market, the goal meter is Economic Value Added (EVA) which is a stricter version than the "REI" since it considers the yield per share.
As shown in the following diagram, The Goal is accompanied by some "Necessary Conditions" such as: 1) satisfaction of customers and suppliers, 2) satisfaction of employees and workers, 3) care of the environment (ecology), 4) cash flows and some others (no more than 9 in total).
The "ellipse" between the arrows means that any missing "necessary conditions" prevent continuous improvement of the goal. However, it is important to note that "The Goal" should tend to infinity, while the "Necessary Conditions" should only be kept in a competitive range, so that the improvement of the company's goal is always a "win-win" proposition. This is how the continuous improvement of said goal is achieved.
Regarding the "Necessary Conditions" meters, each company can select the ones it deems most convenient, as long as they truly reflect directly what is important in said necessary condition.
For the «La Meta» meter that we will take as the «REI» we need to first define some parameters, so we will talk about «The 3 Dineros»:
# 1 The Money Generated or "TRUPUT" (T), which is the differential between the "Net Sale" and the "Cost of 100% Direct Inputs", for the period of time in question (normally per month).
# 2 The Money Invested by the system or "INVENTORY" (I), which includes the value of assets and inventories at the cost of their raw materials 100% direct, including accounts receivable.
# 3 The Money Spent by the system or "Operating Expenses" (GO), which comprises all the money spent, including: wages, salaries, waste, energy, depreciation, taxes, and everything else.
Given these 3 monies, which normally comprise all the operating monies of a company, we can define the goal as follows:
PROFIT = T - GO
PROFITABILITY = (T-GO) / I
Given the profitability equation, if the company has a profitability of 35% per annum and the bank is lending at 25% per annum, then the "Effective Return on Investment" REI = 10%.
Given the simplicity of the «T, I and GO» meters proposed by «TOC», it is possible that the entire organization can understand them and therefore can influence them favorably.
Some of you will say "it doesn't seem right to me that the whole organization knows the operating profits of the company", no problem, you can use these same meters in the form of relationships, such as:
PRODUCTIVITY = T / GO
ROTATION = T / I
These relationships do not have units and are therefore only numbers, but they are 100% directly related to the company's "Goal", which is very important since it is the only variable that we want to improve to infinity.
CONSULTING THEORY OF RESTRICTIONS - USE OF THE THEORY OF RESTRICTIONS AND HANDLING QUEUES AT THE START OF THE MANAGEMENT OF THE MAINTENANCE FUNCTION
The theory of restrictions is basically focused on the search for the perfect flow of goods or services through a balanced, coordinated and synchronized value chain of workstations, thus achieving lower operating costs, reducing inventories and increasing sales.
In the case of a maintenance department, all of the above applies, since on the one hand, the maintenance function is nothing more than an ordered set of activities that add value to a "service provided", from a known initial condition to a condition Final that must comply with the quality and safety parameters established or agreed between the entity in charge of adding value (Maintenance Department) and the one that receives it (internal customers) in a given time. Since the service provided is an intangible asset, we can take the "work request" as a tangible element of the service in its initial condition, the "work order in process" as a tangible element of the service in transit and the "completed work order" as an element. tangible service in its final condition.
On the other hand, regarding the expected results, we can establish a direct relationship, since operating costs are maintenance expenses, inventories would be represented by work orders (unattended and in transit) and sales are can be directly associated with the level of service (number of requests handled in a given amount of time).
According to the theory of constraints, the first step for implementation is to identify bottlenecks (service stations that determine the speed of flow in the system), then priorities are assigned to the jobs to be executed and finally the system is balanced.. This process is repetitive, since as the external or internal conditions of the system change, new bottlenecks appear, which brings with it new corrective actions.
In general, work requests come from three main sources: results of preventive and predictive maintenance, requisitions or needs of the productive areas or general plant services, and modifications aimed at addressing the improvements in the processes that are related to the increase in production, safety and quality or, the reduction of costs or risks of environmental impact.
The first thing to do is build the process map of the maintenance function and simulate the flow of tangible elements through it, then, the different workstations must be identified and the slowest one selected; This station will be identified as a "bottleneck" and will determine the speed to process work orders for the entire system, so you must make sure to keep it always busy and with a number of work orders waiting at your entrance to be processed. Next, the average time it takes for the bottleneck to process work orders that arrive at the station should be measured. If the bottleneck processing time matches the demand for jobs to be performed, no need to worry,But if the service demand is higher than the capacity of the bottleneck to process it, a balance must be made in the system assigning part of the work to other stations or find a way to expand the capacity of the bottleneck by granting it more resources (human, technical or economic).
As the bottleneck is the slowest workstation, it is logical to think that at the entrance of it a row or "queue" of tangible elements will be formed to be processed, the amount of elements present in this row is directly proportional to the speed of the stations prior to the bottleneck. According to the theory of restrictions, the queue of tangible elements of our system is nothing more than inventory, which we must reduce but at no time eliminate, since we would leave our bottleneck with no work to do and this situation would have a direct impact on our service level. If we know the rate of processing of tangible elements of a workstation,It does not make sense to place more work at the entrance of the latter than she can do because an excessive number of service orders will accumulate in transit, which have associated costs such as material in stock, planning time, labor, advance payments. service contracts, etc. It is preferable to have the upstream workstation paralyzed and not processing more inventory. However, each station's “free time” can be used by allocating its resources to other stations to balance the system or increase the value-adding flow of our maintenance function.It is preferable to have the upstream workstation paralyzed and not processing more inventory. However, each station's “free time” can be used by allocating its resources to other stations to balance the system or increase the value-adding flow of our maintenance function.It is preferable to have the upstream workstation paralyzed and not processing more inventory. However, each station's “free time” can be used by allocating its resources to other stations to balance the system or increase the value-adding flow of our maintenance function.
PROCESS DESIGN WITH TOC AND ACHIEVE CONTROL WITH TOC
What is the number of items in queue that we must wait for the input of a workstation?
If we know the actual or ideal average service time of the station and the arrival rate of tangible items, we can calculate the number of items in real or ideal waiting to be served using the simple queue model (Little's formula) for stations of Single workstations and the M / M / S model for multi-server workstations. It is important to note that the tangible elements that reach the queue do not necessarily have to wait for all the elements in front of it to be processed; Let us remember that according to the theory of restrictions, after identifying the bottleneck, the priorities for the execution of the service must be established, which, in our case, can be done by applying criticality analysis studies on productive assets,These studies will give a criticality or priority index to the elements, since they are directly associated with interventions or services aimed at ensuring the operational continuity of the equipment.
The calculated number is an indicator that will allow us to know if the workstation is working correctly, or if due to some variation in the statistical distribution that characterizes the arrival of tangible elements, we must balance the complete system. A number of items in the queue controlled around a set value means a good management of the maintenance function in the planned state, since all the stations are fulfilling their work in the expected time and the demand for services has been controlled.
Surely at the beginning of your management, you will have to work a lot to lower the number of items in the queue to the calculated value, but in a short time, the value of the queue will be well below what was expected, then; What happens if the number of items in the queue decreases to a value much lower than desired? This condition has two interpretations, first, it indicates that your station is working more efficiently, in fact, it is now able to meet more demand and therefore handle more flow. Second, it means that something is wrong with the upstream stations, it may be that new bottlenecks appear, even the sources that generate requests may become one of them. For this reason,You must be aware of establishing strategies that allow you to meet unmet demands from internal customers in advance. In order to get more work requests, you may need to start applying predictive maintenance techniques or increase existing ones, carry out formal and routine inspections to detect faults, or increase your preventive maintenance plans. It seems contradictory, but you will not have to apply strategies like the ones mentioned above because you have many orders to attend but because you do not have enough orders for the capacity of your system to be fully used.perform formal and routine inspections to detect faults or increase your preventive maintenance plans. It seems contradictory, but you will not have to apply strategies like the ones mentioned above because you have many orders to attend but because you do not have enough orders for the capacity of your system to be fully used.perform formal and routine inspections to detect faults or increase your preventive maintenance plans. It seems contradictory, but you will not have to apply strategies like the ones mentioned above because you have many orders to attend but because you do not have enough orders for the capacity of your system to be fully used.
Always remember the objectives of the theory of constraints, lower inventories, reduce costs and increase the level of service. Any action that is taken to assign or redistribute resources (human, technical or financial) must be oriented and aligned to achieve these objectives.
HOW TO CONTROL THE SYSTEM? WHAT EXACTLY DOES THE BM (BUFFER MANAGEMENT) METHOD CONSIST OF?
It consists of taking advantage of the constraints programs and the definition of buffers to control whether the materials reach the constraints early enough so that the program can be continued. In other words, the entire plant is not controlled, but only the buffers. Periodically, the actual content of each buffer is observed, it is compared with the content that it should have according to the plan, and action is taken to correct any deviations.
This control method is also the mechanism that allows setting the priorities of corrective maintenance of machines, dynamically assigning personnel to jobs, assigning priorities to manufacturing orders in a machine, etc.
In our next and last note on Operations management we will analyze the meaning of Step 4 of the TOC Focus Process, we will talk about the types of existing production systems (VATI Analysis), we will analyze the advantages and disadvantages of using TOC-based software to implement the method. and we will discuss the particular case where the restriction is labor force.
In recent years, much has been said about new business management philosophies. Total Quality, Just in Time, Reengineering, Theory of Constraints and Intelligent Organizations are perhaps the best known.
But… are they really new? Do they differ so much from each other? In my opinion, the answer to these questions is "Yes and No." You wonder why. Well, nowadays, and after long 50 years of applying the "General Systems Theory", we are used to hearing and using expressions such as "ecosystem", "computer system", "electrical system" and others. The development of scientific disciplines that rigorously employ Systemic Thinking has been spectacular.
Paradoxically, it is also often stated that "the company is a system", even when in the common denominator of the cases, the business structures seem to be based on bases opposed to Systemic Thinking. In most companies, operating policies and resource evaluation measures (people, machinery, etc.) are based on Cartesian Thought, that is, the way of seeing the world that ruled until the appearance of the General Theory Systems.
Total Quality, Just in Time, Reengineering, Theory of Constraints and Intelligent Organizations are based on Systemic Thinking and aim to make our organizations function according to this paradigm. Each of them provides tools to facilitate the necessary paradigm shift in the company. Tools, generally complementary to each other.
In the case of the Theory of Constraints, its contribution can be divided into two groups:
The Thinking Process: Set of tools that facilitate the analysis and search for systemic solutions for problematic situations.
Robust applications based on Systems Thinking and Operations Research methods: Production, Operations, Supply Chain, Project Management, Decision Making, etc.
In abbreviated form, we could say that the Theory of Constraints is based on the following premises:
The goal of any for-profit company is to earn money on a sustained basis, that is, by meeting the needs of customers, employees, and shareholders. If you are not making unlimited profits, it is because something is preventing you: your restrictions. Every business has a few restrictions that prevent it from making more money.
Talking about restrictions is not synonymous with scarce resources; it is impossible to have an infinite amount of resources. Restrictions, those that prevent an organization from achieving its highest performance in relation to its Goal, are wrong policies.
The only real way to improve the functioning of an organization, therefore, is to identify and eliminate its restrictions.
DBR (Drum-Buffer-Rope) is a planning, programming and execution methodology that appears as a result of applying TOC to the programming of a factory. DBR perfectly applies the TOC programming mechanics and makes it easy to understand and implement in the plant. This simplicity is what makes DBR so powerful.
The Drum refers to the bottlenecks (resources with restricted capacity) that mark the passage of the entire factory.
The Buffer is a time-based shock absorber that protects the throughput from day-to-day interruptions (usually attributed to the famous Mr. Murphi) and ensures that the Drum never run out of material.
Instead of the traditional Safety Inventories "based on material quantities" the TOC recommended Buffers are "based on process time". That is, instead of having an additional amount of material, the material is delivered to critical points with some anticipation.
Instead of placing Inventory Buffers at each operation, which unnecessarily increases lead times, companies implementing TOC place Time Buffers only in strategic locations that relate to specific constraints within the system.
The preparation and execution time required for all operations prior to the Drum, plus the Buffer time, is called "Rope -length" (rope length).
The release of raw materials and materials to the plant is then "tied" to the Drum's programming, no material can be delivered to the plant earlier than the "length of the rope" allows, in this way each product is "thrown away by the rope 'through the plant. This synchronizes all operations to the rhythm of the Drum, achieving a rapid and uniform flow of materials through the complex network of processes of a factory.
The DBR (Drum-Buffer-Rope) scheduling method can lead to substantial benefits in the supply chain by ensuring the plant is running at top speed with minimal inventory and meeting unexpectedly high demands.
CONTROLLING THE SUPPLY CHAIN FROM INSIDE THE PLANT
The future competitive advantage that supply chains offer will be to manage the flow of material through the entire plant. Increasing the speed and stability of material flow through plants also has a significant impact on the entire supply chain in which manufacturing is a significant link.
Shortened customer delivery times create a more reliable forecast, or sometimes eliminate the need for forecasting. Reliable deliveries from the plant minimize the need for mattresses in customer orders, thus freeing up capacity that can be used to further increase response.
A faster material flow through the plant, as well as synchronizing that flow with actual customer demand and without the effect of fluctuating lot size policies, also creates stable requirements for suppliers - making them answers from these are better.
Equally significant is the fact that manufacturers of complex products must have local control over execution and scheduling. Corporate edicts about which part to do at a certain time in a plant look good in theory, but work poorly in practice. DBR, with its simplicity, gives the local manager that control while ensuring global coordination
DETERMINATION OF TIME BUFFERS
Stock Buffers are defined to improve the response of the operating system to market demand. This is done through maintaining inventories of in-process or finished products in advance of future demand. This allows orders to be fulfilled faster than normal processing time.
The size and location of the time buffers are determined to protect the amount and timing of the planned Throughput.
Location of Time Buffers: At the end of the process to protect the Throughput and in the CCR's.
Time Buffers Size: Trial and error, starting at 50% of the total processing time.
SUPPLY CHAIN
A manufacturer is generally caught between purchasing and distribution. Although all links in the supply chain must be managed efficiently, the Goal of the Logistics Manager is to coordinate those links towards the common goal of delivering products to the customer in the fastest and most predictable way possible. As Figure 1 shows, the relative value added by various links is different for different markets. Which links are critical depends mainly on the relative value added by them.
Demand Management and Distribution Control For example, if you manufacture products like soap or toothpaste, the critical link in your supply chain is distribution. The objective of the supply chain is to have the correct products on the shelf when the customer passes through the aisle of a supermarket. Unfortunately, the sophisticated distribution network created to ensure that availability can create problems. Ordering policies in your distribution network can cause high fluctuations in demand at the production floor. How is it possible?. If warehouses order in batches of 100 units, because even if they only have a demand for 10, they must order the minimum of 100, according to the policy, and suddenly there is a lack of capacity
Even though demand remains stable at ten units, what the manufacturing plant sees is a lack of capacity, or an excess of it. This problem is increased when you have several tiers in your distribution network, each trying to follow its own policy.
The result - the factory cannot handle the fluctuations it sees, products are not where they are needed, and sales are lost. Your distribution network lacks an effective way to communicate information from the points of sale to the plant without delay. You need to correct this with a real-time enterprise-grade information system.
MRP AND THE THEORY OF RESTRICTIONS
Real-Time MRP for Assembly-Focused Manufacturers
Durable product assemblers (automobiles, for example) typically face problems at the other end of the chain. They have a large number of providers. They use MRP to plan and order supplies according to market demand. What happens when providers are not available? The MRP system washes your hands. However, you still have to solve the problem. MRP systems with massive daily runs do not provide the speed and flexibility to match supplies and demand in real time in various situations, although this is necessary for the business to react reasonably to any fluctuation in supply. The solution in most of these cases is a real-time MRP engine with the capacity for future programming.
MANAGEMENT OF COMPLEX SUPPLY CHAINS
If you manufacture and assemble discreet and complex products, such as appliances or auto parts, the heart of your business is the plant. You have a variety of products and a complex flow of products in your plant. Even if demand were stable and supplies were reliable, you would still have a complex management problem on your hands.
You are probably facing the contradictory situation of low utilization and lots of overtime to get things done on time. Their inventory is large, yet parts are missing at critical assembly points. You manufacture in economically sized batches and costs remain high.
You need detailed programs for your machines, but the data and standards are far from 100% correct. You wonder if the entire plant can really operate in sync? What if something goes wrong? Things break down, Murphy is always on the lookout after all. What can fail will fail. Frequent reprogramming is not the answer, as it will create even more confusion in the plant.
What is needed is a methodology that can make materials flow quickly and predictably even in the most complex and unstable production environments, with volatile demands and supplies. Without a fast and stable flow of materials, there is no way to control the rest of the supply chain. A robust supply chain solution can only be built around a robust plant-level solution for manufacturers of complex products. Drum-Buffer-Rope (DBR), a comprehensive programming, execution and planning methodology based on the Theory of Constraints concepts developed by Dr. Eli Goldratt, has proven to be the most effective for managing these plants.
DBR - MORE THAN ADVANCED PROGRAMMING AND PLANNING
Restriction alone cannot ensure delivery to customers. Support is required from the other resources, which means that the constraint is randomly released when one of the resources feeding it stops. Under DBR, the solution is not to drive the entire plant into violent instability by reacting to every problem, but to protect critical 'Murphy' resources using TIME-BUFFERS (time buffers). With these time-buffers, in a perfect world, jobs will arrive some time before they are needed by the critical resource. However, in the real world, they are delayed - but still in time for the critical resource to keep working.
In addition to maximizing delivery to customers, the other key need in today's plants is to provide rapid response to customers. Having large inventories of finished products is an extremely expensive way to guarantee the required response if market demand cannot be accurately predicted or if the risk of products becoming obsolete is very high due to constant design changes and the introduction of new products. Moving material faster through the plant is the only sensible alternative, especially in plants where queue time takes up more than 80%.
As any production manager can assert, unnecessary inventory blocks the way, and impedes the flow of material. Therefore, DBR indicates that the plant should work only as necessary to meet market requirements, not what is required to keep workers and machines busy. Also, the output time of materials should be controlled by what the bottlenecks can manufacture (with the appropriate time-buffers). This is called tying the start of operations to the bottleneck using the rope (ROPE).
THROUGHPUT ACCOUNTING
a) Modification of accounting techniques, mainly in relation to the presentation of results in something that is called "throughput accounting".
b) This throughput accounting is so ambitious that it gives rise to the “world of throughput”, contrasting it with the “world of costs” and criticizing the conventional methods of identification and determination of costs
c) Orientation of the entire decision-making process to starting from the world of throughput.
d) Production planning in plants where there are bottlenecks, which is then extended to other variables.
And what does throughput accounting mean? In her book "The Goal" E. Goldratt maintains that the objective of any company is to make money; and the indicators to know if a company is making money are:
But it happens that the area where E.Goldratt developed his ideas was, one of the industrial plants, one of the divisions of a large corporation, whose function was to produce and deliver orders taken by a commercial area, which was linked to the plant industrial, solely by the fact that they reported to the same divisional manager. This, which may seem anecdotal, is extremely important, since it clearly shows that all the development of E.Goldratt was carried out in an industrial environment, totally ignoring in its analysis, the existence of other areas, which the company obviously had.
According to E. Goldratt, the goal of an industrial plant is the same as that of the company: to make money; and produce to achieve full use of installed capacity, seeking full absorption of costs, move the industrial plant away from the goal, if these units cannot be sold, increasing the inventory of finished products, or that of production in process, whether the bottleneck is demand or one of the productive resources. In other words, under the circumstances described, high efficiency leads the company in the opposite direction to the goal.
E.Goldratt should know that the concept of efficiency is much broader than producing at maximum capacity. Efficiency begins with the very definition of the productive capacity of the plant; In any case, if due to a decrease in demand or due to partial renewal of some productive resources, the capacity of the plant becomes unbalanced, no person, except the followers of E. Goldratt, would simply think of producing over the maximum capacity of each resource. to take advantage of installed capacity; Because even if he did, there would come a time when the depletion of physical space due to inventory storage would put him on notice of the error, if he is not previously terminated in his functions due to professional negligence.It is known that there are different solutions to try to mitigate the negative effects of operating with idle capacity, but none of them propose the folly of producing for inventories that can never be sold. But it seems that for E. Goldratt yes; then it appears as the "savior", indicating the inconvenience of the procedure by proposing a solution.
Additionally, claiming that the goal of an industrial plant is to make money is at least a forced concept; the one that must earn money is the company as a whole and each part of it must carry out its task in the most efficient way possible so that the company can achieve the objective. If we accept that the objective of an industrial plant is to make money, the same can also be sustained for the canteen, surveillance or administration.
Continuing with his line of development, E. Goldratt argues that the indicators used to know if a company is making money are not adapted to the characteristics of an industrial plant; For this reason, he developed a new set of parameters that, according to him, mean the same thing in terms of goal:
The names that E.Goldratt used for the parameters do not matter. The important thing is to know what you understand by each of them
Note that the word "system" is mentioned in the definitions of each of the parameters; and it is recalled that for E. Goldratt this term means: industrial plant; at least until this stage of its development because, as will be seen later, almost by magic, it begins to speak of the system as a synonym for the company.
In summary, E. Goldratt defines: a parameter for the money that comes in (throughput), another for the money that remains immobilized (inventory), and finally a parameter for the money that goes out (operating expenses).
From this, he understands that progress is being made in terms of the goal, to the extent that throughput is increased and inventories and operating expenses are decreased, placing special emphasis on the relationship that exists between the parameters; in this way:
And he concludes on these relationships: if throughput increases and inventories and operating expenses are not unfavorably modified, net profit, return on invested capital and cash flow increase; The same occurs if operating expenses fall and throughput and inventories do not change unfavorably; On the other hand, if inventories fall and throughput and operating expenses are not unfavorably modified, only the return on invested capital and cash flow are affected, the net profit remaining unchanged.
CRITICAL ANALYSIS OF THROUGHPUT ACCOUNTING
Goldratt began its developments by clearly defining that the indicators to know if a company was making money were: Net profit, Return on invested capital and cash flow. Then he adapted them because he argued that they did not fit an industrial plant; thus were born: Throughput, Inventories and Operating Expenses. Using the parameters according to convenience and with a significant dose of goodwill, it could be argued that originally and taking them exclusively as utility indicators, we are facing a problem of terminology. In this way:
What is Throughput? What is it for?. While accepting that raw material is the only variable cost of production that exists, E. Goldratt did not even realize that there are also variable commercial expenses. Many authors of real worth have fallen into the trap of assuming that throughput is synonymous with marginal contribution; there is not a single line in all of E. Goldratt's books that leads to this assumption. E. Goldratt does not know at all what it is about and believes, or has been led to believe, that throughput can twist the history of a discipline that has been developed and nurtured with the effort of true professionals in the field.
Throughput is just a financial indicator of doubtful utility and proof of this is that in the books after "La Meta" it tried to modify the definition by subtracting from the sale price, in addition to the raw material, the outsourced services, commissions paid to external sellers, customs duties, freight and transportation carried out by third parties. If any reader imagines that she deduces all these concepts because she considers them variables, she is totally wrong. It does so on the basis of the "system" that generates money; throughput, according to E. Goldratt, is to bring fresh money from abroad; therefore, when it is sold, the sale price less the money that must be left abroad enters the company because it belongs to a third party's system. It is money that flows through our system but does not belong to us. According to this,a transport carried out with own vehicles is an operating expense; On the other hand, if it was done with third-party vehicles, deduct the throughput. The key element that defines the categorization of disbursement is the system that generates the money. We wonder what the usefulness of this classification is from a cost and management point of view.
And when it comes to operating expenses, E. Goldratt reaches his highest achievement: he includes salesmen's commissions, secretaries' salaries, direct labor, amortization, dining room expenses, driving force, etc. It does not classify by function or by variability; does not separate into operating costs and capacity; the directionality is unknown; This is a consequence of the fact that for him there is neither the cost of the product nor its utility; everything must be done in total and the company must be controlled as a whole. E. Goldratt argues that the cost of a product is "a mathematical ghost" because it is not possible to allocate operating expenses to the product; but this affirmation is not made from a deep conviction as the defenders of variable costing might have;their arguments come from ignorance. Proof of this is the following sentence taken verbatim from his books: »before, operating expenses were applied in proportion to MOD's costs. Today it is not possible due to technological progress. That is why cost accounting is out of date.
BUILDING AND EVAPORATING THE CLOUDS OF CONFLICT
The existence of this chain implies that there are dependent resources - a step cannot be done before the previous one - and statistical fluctuations that affect the flow of product through the resources.
This reality can occur in at least three scenarios: Supply, Operations and Market.
To achieve continuous improvement in the case of physical constraints, the Theory of Constraints has developed a cycle of five simple steps that guarantee a focused approach to the goal:
Identify the restriction
Decide how to exploit it
Subordinate everything else to that decision
Raise the restriction
If the restriction has been broken in a previous step, go back to the first step.
This five-step cycle fulfills the objective regarding the economic exploitation of our physical restrictions, but to achieve the goal of "More Profits Now and in the Future" it is necessary to have a methodology for solving political restrictions, which are the most common in any type of company and are those that have a strategic impact in the short, medium and long term.
The Goldratt Institute has developed five techniques to address Policy Constraints:
Trees of Current Reality
Technique that is used to detect spinal problems. These core issues are few (they represent policy constraints) and are responsible for the undesirable effects we observe in our organizations.
Cloud Evaporation
Technique for the generation of simple and effective solutions to conflicts, without appealing to commitment.
Trees of Future Reality
Technique to evaluate the solution, find negative branches and how to neutralize them.
Prerequisite Trees
Technique to identify and relate the obstacles that will be encountered when implementing the solution, since each solution creates a new reality.
Transition trees
Final technique, in which the tactic that will allow the solution obtained to be implemented successfully is materialized. Here economic needs and expected benefits are quantified. Define the Action Plan. >
The CURRENT REALITY TREE is the tool created to carry out Step 1. The CONFLICT CLOUD and the FUTURE REALITY TREE are the tools created to facilitate Step 2. The PRE-REQUIREMENT TREE and the TRANSITION TREE are the tools created to facilitate Step 3.
Step 1: IDENTIFY the company restrictions.
This Step is, in my opinion, the most difficult since we usually call "restriction" the symptoms of not using our system correctly. In general, we feel that we have thousands of restrictions: lack of people, lack of machines, lack of materials, lack of money, lack of space, macroeconomic policies, absenteeism, excess stocks, etc.
General Systems Theory holds that whatever the system and its goal, there are always a few elements that determine its capacity, no matter how complex or complicated.
How to identify those elements?
First of all, dear reader, restriction is not synonymous with scarce resource. It is impossible to have an infinite amount of resources. There are basically two types of restrictions:
Physical: Shortage of raw materials, a very loaded machine, people with a certain skill, the Market, etc.
We can only say that there are physical restrictions when the political restrictions have already been removed.
Policies: Erroneous formal or informal rules, not aligned or in conflict with the goal of the system.
What type of restrictions do you think are more common in our companies: political or physical? Which ones do you think are easier to identify?
In most companies the restrictions are POLITICAL. That is, formal or informal rules that prevent the system from achieving better performance in relation to its goal.
Due to the existence of political restrictions, it is not possible to get the most out of the company's scarce resources.
The statements in the previous paragraph seem like an exaggeration but they make a lot of sense when we consider that organizations are systems and that we are not managing them as such.
The fact that there are political restrictions is very good news since if we could identify and eliminate them we could significantly increase the profitability of our system without significant investments of money. And this reminds us of the question not yet answered:
HOW TO IDENTIFY THE SYSTEM RESTRICTIONS?
TOC proposes to build a TREE OF CURRENT REALITY, which is a technique that makes it possible to make explicit the interdependencies that exist in the system under study and to find the core problems (or restrictions).
A fairly typical error in Operations (Production and Services) is to consider that the restriction is the place where stocks accumulate within the system. This is not always correct, but depends on the interdependencies that exist. Let's look at some simple examples:
In a hospital a doctor has a room full of patients. One might think, hastily, that the restriction is the doctor. Analyzing the interdependencies it was discovered that, once the patient enters the office, the doctor is several minutes waiting for the corresponding medical history to arrive. What is the restriction? Is it a physical or political restriction?
In a factory there is a lot of work-in-progress stock in front of Machine A and Assembly Station B. One might hastily think that both are constraints. Analyzing the interdependencies, it was discovered that machine A supplies station B with one of the components necessary to carry out the assembly operation and that in front of machine B there is a stock of all components except for that coming from machine A and another purchased component. to an external provider. Purchasing says that the supplier in question does not deliver the component due to non-payment. What are the system restrictions? Are they physical or political restrictions?
These simple examples show that it is essential to make explicit all the interdependencies that exist in a system since in this way it is possible to discover how the decisions of one area or department impact on other areas or departments. It is essential, then, to make the Actual Reality Tree of the system
DECIDE HOW TO EXPLOIT THE RESTRICTIONS.
The restrictions prevent the system from achieving a better performance in relation to its Goal (be it making money, caring for the health of the population, increasing the cultural level of the Society, etc.). It is essential, then, to carefully decide how we are going to use them, how we are going to exploit them.
Depending on what the system constraints are, there are numerous methods to get the most out of them:
- Methods and algorithms that facilitate this task can be found in the abundant bibliography on Operations Research. Care must be taken, however, to apply these methods only to constraints and not to all resources.
In "The Haystack Syndrome," a method of exploiting an internal physical restraint is presented. In another section of the same book, it is analyzed in detail what it means to EXPLODE the system restrictions in the context of the Production area.
Simple examples of how to exploit a constraint are as follows:
- The restriction is a machine: the most skilled operators should be assigned to it, quality control should be done before it processes the pieces, lunch stops should be avoided (Rotating people), it should be avoided Without working due to lack of materials (Incorporation of time buffers), it should be provided with an optimal program where every minute is used to fulfill commitments with clients, etc.
- The restriction is in the Market (There are not enough sales): Make sure that all orders are dispatched within the deadline agreed to with customers. There is no excuse since the company has more production capacity than the market demand. Many times, when demand falls, production capacity is reduced (Layoffs), this leads to the committed deadlines not being met, which in turn further reduces sales, which increases layoffs, etc.
- The restriction is a raw material (The supply is less than the needs of the company): Minimize scrap and losses due to poor quality, do not manufacture quantities greater than those that will be sold in the short term, etc.
Step 3 - SUBORDINATE everything else to the previous decision.
This step consists of forcing the rest of the resources to function at the rate set by the system restrictions, as defined in the previous step. As the company is a system, there is interdependence between the resources that compose it. For this reason, it does not make sense to require each resource to act obtaining the maximum performance with respect to its capacity, but rather it must be required to act in a way that facilitates that the restrictions can be exploited as decided in Step 2.
It is essential, then, to take into account the interdependencies that exist if subordination is to be carried out successfully. The CONFLICT CLOUD and the FUTURE REALITY TREE can be of great help in this step.
Step 4 - ELEVATE company restrictions.
Further improvement requires increasing the capacity of the restraints. This is the meaning of ELEVATE.
Examples of RAISE system constraints are:
Buying a new machine similar to the restriction.
Hiring more people with the right skills
The incorporation of a new supplier of the materials that are currently restriction
The construction of a new factory to meet a growing demand.
In general, our tendency is to carry out this step without having completed steps 2 and 3. By doing so we are increasing the capacity of the system without having yet obtained the maximum benefit from it as it was originally defined.
Since Step 4 typically involves actions that require a lot of effort, time, and money, it is recommended that you do not do it until you are sure that the previous steps have been implemented successfully. This way of proceeding will also help to generate more own resources to face the necessary investments.
Step 5 - Return to Step 1.
As soon as a restriction has been raised, we must ask ourselves if it continues to be such or if there are now other resources with less capacity. We must, then, return to Step 1, starting the Process again.
It is important to make a warning here: BEWARE OF INERTIA! In steps 1 to 3 we have defined the operating rules of the company considering the existing restrictions at that time. If the restrictions have changed, all those rules must be modified.
At this time there is no doubt that any organization, if it wants to survive, must embark on a Process of Continuous Improvement. Continual Improvement IS NOT FREE. The Targeting Process proposed by TOC is designed to ORIENT the improvement efforts in order to achieve the maximum impact at each moment of the system's life.
REFERENCES AND WEB LINKS:
| Published Work of Industrial Engineering (UPIICSA - IPN) |
| Engineering of Work Methods |
| http://www.monografias.com/trabajos12/ingdemet/ingdemet.shtml |
| Work Measurement Engineering |
| http://www.monografias.com/trabajos12/medtrab/medtrab.shtml |
| Quality Control - Its Origins |
| http://www.monografias.com/trabajos11/primdep/primdep.shtml |
| Market research |
| http://www.monografias.com/trabajos11/invmerc/invmerc.shtml |
| Method Engineering - Production Analysis |
| http://www.monografias.com/trabajos12/andeprod/andeprod.shtml |
| Measurement Engineering - Standard Time Applications |
| http://www.monografias.com/trabajos12/ingdemeti/ingdemeti.shtml |
| Chemistry - Atom |
| http://www.monografias.com/trabajos12/atomo/atomo.shtml |
| University Physics - Classical Mechanics |
| http://www.monografias.com/trabajos12/henerg/henerg.shtml |
| UPIICSA - Industrial Engineering |
| http://www.monografias.com/trabajos12/hlaunid/hlaunid.shtml |
| Mechanical Testing (Destructive Testing) |
| http://www.monografias.com/trabajos12/pruemec/pruemec.shtml |
| Classical Mechanics - One-Dimensional Movement |
| http://www.monografias.com/trabajos12/moviunid/moviunid.shtml |
| Quality Control - Shewhart Control Charts |
| http://www.monografias.com/trabajos12/concalgra/concalgra.shtml |
| Chemistry - UPIICSA Physicochemistry Course |
| http://www.monografias.com/trabajos12/fisico/fisico.shtml |
| Methods Engineering - Work Sampling |
| http://www.monografias.com/trabajos12/immuestr/immuestr.shtml |
| Biology and Industrial Engineering |
| http://www.monografias.com/trabajos12/biolo/biolo.shtml |
| Linear Algebra - UPIICSA Exams |
| http://www.monografias.com/trabajos12/exal/exal.shtml |
| Electricity Laboratory Internship (UPIICSA) |
| http://www.monografias.com/trabajos12/label/label.shtml |
| UP Chemistry Laboratory Internships |
| http://www.monografias.com/trabajos12/prala/prala.shtml |
| Resnick, Halliday, Krane Physics Problems (UPIICSA) |
| http://www.monografias.com/trabajos12/resni/resni.shtml |
| Biochemistry |
| http://www.monografias.com/trabajos12/bioqui/bioqui.shtml |
| Theory of the Company |
| http://www.monografias.com/trabajos12/empre/empre.shtml |
| Code of ethics |
| http://www.monografias.com/trabajos12/eticaplic/eticaplic.shtml |
| Engineering Methods: Systematic Analysis of Production 2 |
| http://www.monografias.com/trabajos12/igmanalis/igmanalis.shtml |
| University Physics - Oscillations and Harmonic Motion |
| http://www.monografias.com/trabajos13/fiuni/fiuni.shtml |
| Chemical Production - The world of plastics |
| http://www.monografias.com/trabajos13/plasti/plasti.shtml |
| Plastics and Applications - Case Study at UPIICSA |
| http://www.monografias.com/trabajos13/plapli/plapli.shtml |
| Production Planning and Control (PCP - UPIICSA) |
| http://www.monografias.com/trabajos13/placo/placo.shtml |
| Operations Research - Linear Programming |
| http://www.monografias.com/trabajos13/upicsa/upicsa.shtml |
| Legislation and Mechanisms for Industrial Promotion |
| http://www.monografias.com/trabajos13/legislac/legislac.shtml |
| Operations Research - Simplex Method |
| http://www.monografias.com/trabajos13/icerodos/icerodos.shtml |
| Industrial Psychosociology |
| http://www.monografias.com/trabajos13/psicosoc/psicosoc.shtml |
| Legislation for Industrial Promotion |
| http://www.monografias.com/trabajos13/legislac/legislac.shtml |
- PRODUCTION PLANNING AND CONTROL: ASSEMBLY LINE BALANCING: MIXED AND MULTI-MODEL LINES www.gestiopolis.com/recursos/documentos/fulldocs/ger1/pcplinen.htm PRODUCTION PLANNING AND CONTROL - LINE BALANCING www.gestiopolis. com / resources / documents / fulldocs / ger1 / pycdelapro.htm FOUNDATIONS OF THE ECONOMY OF QUALITY SYSTEMS www.gestiopolis.com/recursos/documentos/fulldocs/fin/fundelacal.htm SALARY PAYMENTS: SALARY AND INCENTIVE PLAN IN INDUSTRIAL ENGINEERING www. gestiopolis.com/recursos/documentos/fulldocs/rrhh/pagosal.htm STANDARD TIME MANUAL www.gestiopolis.com/recursos/documentos/fulldocs/ger/mantiemesivan.htm INTRODUCTION TO INDUSTRIAL ENGINEERING www.gestiopolis.com/recursos/documentos/fulldocs /ger1/introalaii.htm OPERATIONS INVESTIGATION - NETWORKS AND PROJECT MANAGEMENT www.gestiopolis.com / resources / documents / fulldocs / ger1 / iopertcpm.htm PRODUCTION PLANNING AND CONTROL - MRP http://www.gestiopolis.com/recursos/documentos/fulldocs/ger1/mrpivan.htm NON-DESTRUCTIVE TESTS - ULTRASOUND http: // www.gestiopolis.com/recursos/documentos/fulldocs/ger1/disultra.htm COMPUTER AIDED DESIGN AND MANUFACTURING - INTRODUCTION TO THE CNC
| Published Works of Pneumatics in Industrial Engineering |
| UPIICSA compressed air |
| http://www.monografias.com/trabajos13/compri/compri.shtml |
| Pneumatics and Industrial Engineering |
| http://www.monografias.com/trabajos13/unointn/unointn.shtml |
| Pneumatics: Air Generation, Treatment and Distribution (Part 1) |
| http://www.monografias.com/trabajos13/genair/genair.shtml |
| Pneumatics: Air Generation, Treatment and Distribution (Part 2) |
| http://www.monografias.com/trabajos13/geairdos/geairdos.shtml |
| Pneumatics - Introduction to Hydraulic Systems |
| http://www.monografias.com/trabajos13/intsishi/intsishi.shtml |
| Structure of Hydraulic Circuits in Industrial Engineering |
| http://www.monografias.com/trabajos13/estrcir/estrcir.shtml |
| Pneumatics and Hydraulics - Power Generation in Industrial Engineering |
| http://www.monografias.com/trabajos13/genenerg/genenerg.shtml |
| Pneumatics - Pneumatic Valves (applications in Industrial Engineering) Part 1 |
| http://www.monografias.com/trabajos13/valvias/valvias.shtml |
| Pneumatics - Pneumatic Valves (applications in Industrial Engineering) Part 2 |
| http://www.monografias.com/trabajos13/valvidos/valvidos.shtml |
| Pneumatics and Hydraulics, Hydraulic Valves in Industrial Engineering |
| http://www.monografias.com/trabajos13/valhid/valhid.shtml |
| Pneumatics - Pneumatic Auxiliary Valves (Applications in Industrial Engineering) |
| http://www.monografias.com/trabajos13/valvaux/valvaux.shtml |
| Industrial Engineering Problems in the Field of Pneumatics (UPIICSA) |
| http://www.monografias.com/trabajos13/maneu/maneu.shtml |
| Solenoid Valves in Control Systems |
| http://www.monografias.com/trabajos13/valvu/valvu.shtml |
| Pneumatics and Industrial Engineering |
| http://www.monografias.com/trabajos13/unointn/unointn.shtml |
| Structure of Hydraulic Circuits in Industrial Engineering |
| http://www.monografias.com/trabajos13/estrcir/estrcir.shtml |
| Energy saving |
| http://www.monografias.com/trabajos12/ahorener/ahorener.shtml |
| Published Work of Law of the Atoyac School Center |
| Notions of Mexican Law |
| http://www.monografias.com/trabajos12/dnocmex/dnocmex.shtml |
| Notions of Positive Law |
| http://www.monografias.com/trabajos12/dernoc/dernoc.shtml |
| Civil Family Law |
| http://www.monografias.com/trabajos12/derlafam/derlafam.shtml |
| Amparo trial |
| http://www.monografias.com/trabajos12/derjuic/derjuic.shtml |
| Property crimes and Professional Responsibility |
| http://www.monografias.com/trabajos12/derdeli/derdeli.shtml |
| Individual Work Contract |
| http://www.monografias.com/trabajos12/contind/contind.shtml |
| The Family in Mexican Civil Law |
| http://www.monografias.com/trabajos12/dfamilien/dfamilien.shtml |
| The Family in Positive Law |
| http://www.monografias.com/trabajos12/dlafamil/dlafamil.shtml |
| Article 14 and 16 of the Constitution of Mexico |
| http://www.monografias.com/trabajos12/comex/comex.shtml |
| Individual guarantees |
| http://www.monografias.com/trabajos12/garin/garin.shtml |
| The Family and the Law |
| http://www.monografias.com/trabajos12/lafami/lafami.shtml |
| Published Works of History and Philosophy |
| Understanding Today's World by Ricardo Yépez Stork |
| http://www.monografias.com/trabajos12/entenmun/entenmun.shtml |
| The Power of Self Esteem |
| http://www.monografias.com/trabajos12/elpoderde/elpoderde.shtml |
| Mexico from 1928 to 1934 |
| http://www.monografias.com/trabajos12/hmentre/hmentre.shtml |
| Stage of the Independence of Mexico |
| http://www.monografias.com/trabajos12/hmetapas/hmetapas.shtml |
| Thanks Vicente Fox for the Dedocracy !!! |
| http://www.monografias.com/trabajos12/hmelecc/hmelecc.shtml |
| The Profile of Man and Culture in Mexico |
| http://www.monografias.com/trabajos12/perfhom/perfhom.shtml |
| Religions and morals |
| http://www.monografias.com/trabajos12/mortest/mortest.shtml |
| Moral - Salvifichi Doloris
www.monografias.com/trabajos12/morsalvi/morsalvi.shtml |
| The government of General Manuel González |
| http://www.monografias.com/trabajos12/hmmanuel/hmmanuel.shtml |
| Jose Lopez Portillo |
| http://www.monografias.com/trabajos12/hmlopez/hmlopez.shtml |
| Museum of Cultures |
| http://www.monografias.com/trabajos12/hmmuseo/hmmuseo.shtml |
| Man and the Robot: In Search of Harmony |
| http://www.monografias.com/trabajos12/hommaq/hommaq.shtml |
| History of Mexico - The Laws of Reform |
| http://www.monografias.com/trabajos12/hmleyes/hmleyes.shtml |
| History of Mexico - Inquisition in New Spain |
| http://www.monografias.com/trabajos12/hminqui/hminqui.shtml |
| History of Mexico - The French Intervention |
| http://www.monografias.com/trabajos12/hminterv/hminterv.shtml |
| History of Mexico - First Centralist Government |
| http://www.monografias.com/trabajos12/hmprimer/hmprimer.shtml |
| History of Mexico - El Maximato |
| http://www.monografias.com/trabajos12/hmmaximt/hmmaximt.shtml |
| History of Mexico - The War with the United States |
| http://www.monografias.com/trabajos12/hmguerra/hmguerra.shtml |
| Mexico: Embracing New Culture? |
| http://www.monografias.com/trabajos12/nucul/nucul.shtml |
| Ranma Manga (English only) |
| http://www.monografias.com/trabajos12/ranma/ranma.shtml |
| Fraud of the Century |
| http://www.monografias.com/trabajos12/frasi/frasi.shtml |
| Jean michelle basquiat |
| http://www.monografias.com/trabajos12/bbasquiat/bbasquiat.shtml |
| The Sense of Humor in Education |
| http://www.monografias.com/trabajos12/filyepes/filyepes.shtml |
| Teaching Engineering versus Privatization |
| http://www.monografias.com/trabajos12/pedense/pedense.shtml |
| Learning process |
| http://www.monografias.com/trabajos12/pedalpro/pedalpro.shtml |
| Giovanni Sartori, Homo videns |
| http://www.monografias.com/trabajos12/pdaspec/pdaspec.shtml |
| Life: Things are known by their operations |
| http://www.monografias.com/trabajos12/lavida/lavida.shtml |
| What is Philosophy? |
| http://www.monografias.com/trabajos12/quefilo/quefilo.shtml |
| Sensitive knowledge |
| http://www.monografias.com/trabajos12/pedyantr/pedyantr.shtml |
| Authors and schools comparison |
| http://www.monografias.com/trabajos12/pedidact/pedidact.shtml |
| Philosophy of education |
| http://www.monografias.com/trabajos12/pedfilo/pedfilo.shtml |
| Analysis of the psychopathology of memory |
| http://www.monografias.com/trabajos12/pedpsic/pedpsic.shtml |
| Company and family |
| http://www.monografias.com/trabajos12/teoempres/teoempres.shtml |
| Philosophical Anthropology |
| http://www.monografias.com/trabajos12/wantrop/wantrop.shtml |
| Definition of Philosophy |
| http://www.monografias.com/trabajos12/wfiloso/wfiloso.shtml |
| Review of the Magna Didactic Book |
| http://www.monografias.com/trabajos12/wpedag/wpedag.shtml |
| Man before the problems and limits of Science |
| http://www.monografias.com/trabajos12/quienes/quienes.shtml |
| Review of the book Froebel. The education of man |
| http://www.monografias.com/trabajos12/introped/introped.shtml |
| Philosophical Anthropology |
| http://www.monografias.com/trabajos12/antrofil/antrofil.shtml |
| Technical calculation memory |
| http://www.monografias.com/trabajos12/electil/electil.shtml |
| Calculation memory |
| http://www.monografias.com/trabajos12/elplane/elplane.shtml |
- http://www.streamtech.com.mx/serv1-main.htm
