Summary
After analyzing the importance of managing the logistics chain with an approach based on TOC and the repercussion of this on the performance of service companies, this work is responsible for providing the relationship between each of the factors that make up the logistics system, as well as a technology to improve them.
The theoretical analysis carried out is the sediment for the formulation of the Model for the management of physical restrictions in the analysis of logistics systems. Based on the fact that the fundamental basis of any company is its logistics system, which boils down to three fundamental subsystems: Supply Management, Transformation Management and Distribution Management; who are in charge of converting the inputs into outputs, there is a relationship between them that forms the coordination stage, closely associated with this is the business triangle that finds in each of its vertices the main elements that determine the success of modern companies: HR, the market and the logistics system,the interrelation of these and the influence of senior management on them guarantees the future performance of the organizations and therefore the path that each of them will follow. In the upper stage, the system will be affected by internal and external factors that inhibit its actions (restrictions) which condition its performance, "Bottleneck Effect" (Abat; Caballero; Molina), in this way the organization will be forced to plan your level of service according to the possibilities you have and the aspirations of the customers who will be the measurer of each of your actions, so the function of this model is to maximize customer satisfaction regardless of what and where you are. the restriction. Improvement as a last step on the road to LA META is only achieved if the level of service,Located symbolically, at the top of the bottle it fits perfectly with customer satisfaction and the flow of information is in line with the proposed objectives.
It is important to keep in mind that the interest groups to which the entity responds will be highly involved in all this process of value creation in the product / service, putting pressure on the bottleneck or becoming this when the entity does not have the necessary capacity to respond to their interests, so they must be treated with the same care as clients because they will be treated in the end, even if indirectly.
The procedure for managing physical restraints consists of four fundamental stages. These are briefly reflected below, describing their definition, objectives, tasks and methods. As well as the techniques that must be applied to fulfill the final objective.
Stage I. Characterization of the system.
This stage is aimed at familiarizing the researcher with the entity under study.
Goals:
- Familiarization and characterization of the organization. Knowing the long-term strategic objectives of the organization. Delimiting the scope of the company's logistics system, specifying the borders for analysis.
Chores:
2.1 Characterize the system.
In the characterization, a detailed study will be made of all the parts and components that make up the system.
2.1.1 Characterization of the service unit.
A global analysis of the current situation of the entity will be carried out, including in this a brief historical review of the organization, relationship with customers, as well as competitors, organizational structure and characteristics of the workforce. In the characterization, aspects such as: the location of the entity, merits and distinctions achieved, among others, must appear.
2.1.2 System classification.
The types of production or service systems are determined by a set of characteristics given by the action of external and internal factors, taking into account the criteria set forth by Doctors Ana Julia and Acevedo. These are: producer-consumer relationship, way of executing production and element to be optimized.
The producer-consumer relationship, depending on the type of system and the characteristics of the production or service process, has different classification criteria.
When the production is supplied to the warehouse for the purpose of maintaining a certain level of inventory, consumers receiving their requests from said reserves, the system works against the warehouse. To avoid any contingency in the supply, it is customary to work with a margin of safety in the inventory.
If the customer receives the product or service directly, without prior storage, we find beforehand a direct delivery without coverage; if, on the other hand, the production or service is achieved before the time it is delivered, so it must be temporarily stored until it reaches the consumer, then it is the case of a direct delivery with coverage.
For its part, the way of executing production is determined by a group of factors that will lead to the specific operation of the system.
It will be by rhythm when the production or service is carried out rhythmically throughout the year or that generally very little affectation occurs in the rhythm of production or service provision.
The way to execute the programmed production depends on a precise knowledge of the level of the demand and what will be its behavior. This system can take three forms:
- programmed at fixed amount: it is presented when the batch size is the same in each launch, that is, it is constant; programmed at fixed frequency: when the launch frequency is constant, the batch size of each launch may be different; programmed Irregular - varies both the lot size and the frequency of the launch.
If, on the other hand, there is no exact knowledge of the level of the demand, nor what its behavior will be, and this occurs during the execution of the planned period and the request is made by the consumer upon request or order to the producer, the form of run production will be per order.
Another characteristic to evaluate is the element to be optimized, it can be: the duration of the cycle, the use of energy, the use of labor power, the use of capacity or the use of raw materials.
Another form of classification for service units is taking into account the service matrix proposed by Schmenner. This matrix indicates the way in which the services can be located. This shows four types of service operations: the service factory (low interaction and adaptation and labor intensity), the service workshop (highly automated services, with a certain degree of adaptation), the mass service (high level labor and low interaction and adaptation) and professional services (high level of adaptation and very little automation).
2.1.3 Description of the service cycle.
All services are supplied within a service cycle. The cycle begins at the point where the customer first comes into contact with the service delivery system. It continues with each subsequent contact the customer makes with anyone in the facility. In each of these steps, the customer forms a conscious and unconscious impression of whether or not the entity meets their needs.
The service cycle is activated every time the customer contacts our business. With it we can look at the organization through the eyes of the clients and see the business from their point of view.
This name includes a detailed description of the way in which the customer perceives the service in each of the parts that make up the system, from its arrival to the moment of dismissal.
2.1.4 Productivity indicators.
There are three criteria commonly used in evaluating the performance of a system, which are closely related to quality and productivity: efficiency, effectiveness and efficacy. However, they are sometimes misinterpreted, misused, or considered synonymous; Due to this, it is convenient to clarify their definitions and their relationship with quality and productivity.
Efficiency: it is used to account for the use of resources or fulfillment of activities with two meanings; the first as a relationship between the amount of resources used and the amount that had been estimated or programmed to be used; the second, as the degree to which the resources used are used to transform them into products. Both definitions are closely linked to one aspect of productivity: that of the use of resources; however, as previously stated, it does not account for the quality of the product or service as much, so it expresses part of the meaning of productivity. The exaggeration of the importance of efficiency leads us to place more emphasis on the management of quality resources and productivity. These are the so-called efficiency styles: spending budget compliance,use of available hours, carrying out activities, etc., are very common expressions characteristic of efficiency.
However, due to its limitations, the concept of efficiency leads us to always keep in mind the idea of cost, through the use we make of resources.
Effectiveness: it is the relationship between the results achieved and the results that we had set for ourselves and accounts for the degree of fulfillment of the objectives that we have planned: quantities to produce, customers to have, purchase orders to place, etc. When considering effectiveness as the only criterion, one falls into the gimmicky styles, those where the result is important, no matter at what cost. Effectiveness is linked to productivity through impact on the achievement of greater and better products (according to the objective), however it suffers from the notion of use of resources.
Efficacy: values the impact of what we do, the product or service we provide. It is not vast to produce with 100% effectiveness the service or product that we set ourselves both in quantity and quality, but it is necessary that it be adequate, the one that will really satisfy the customer or impact our market. As it can be deduced the efficacy is a criterion closely related to what we have defined as quality (suitability for use, customer satisfaction), however in the latter in a broad sense (quality of the process, systems, resources), the efficacy must be used in conjunction with the two previous criteria.
2.1.5 Calculation of financial ratios.
This analysis is carried out with the objective of determining to what extent the generation of money by the system is found and what elements are slowing its development. For this, it is necessary to rely on data taken from the balance sheet and the income statement. From this information, the financial ratios are calculated:
Reasons for Solvency
1. Solvency: its value is generally considered acceptable if it is greater than two, but the exact determination of an acceptable value depends largely on the field in which the company operates. A solvency ratio of one could be considered acceptable in a service company, but it could not be accepted in any way in a manufacturing company.
…(one)
If the system is solvent, it means that the entity has enough current assets to pay its current liabilities in a fairly short term.
2. Liquidity: this shows the possibilities that companies have to make their payments immediately.
…(two)
A system is liquid when it has enough cash to pay its current liabilities in a fairly short term. This relationship must be greater than one, otherwise the entity is considered to be illiquid.
3. Debt Ratio: it allows to know to what extent the system has been investing to develop its operations.
…(3)
It is stated that every system must invest to develop, so it must incur debts, that is why this ratio should not be equal to zero and should move in an optimal range, established between 0.30 - 0.60, that is, there must be a minimum amount of indebtedness. Below this value, the system will have little development in its operations; Above the upper limit, you are running the risk of going bankrupt because you have too many debts.
If it moved in this range and presented difficulties in the above reasons, the entity would not be in favorable conditions to pay its debts, so it must be careful to continue borrowing.
Activity reasons.
1. Rotation of inventories:
…(4)
It indicates to what extent the transformation process has been developed. The higher this value is, the better. It is compared with its historical values or the branch to which it belongs.
2. Collection cycle:
…(5)
Where: TÞ term set for collection.
It shows how this cycle has been developing: if this value is less than the established term, it would be indicating a good behavior of the collection activity; otherwise it would indicate delays in this activity, which could affect the liquidity of the company.
3, Payment cycle:
… (6)
Where: TÞ deadline for payment.
Indicates to what extent this activity is behaving. If this value is greater than the established term, it would indicate insufficiency of the system to execute its payments.
Profitability reasons
1. Ratio of sales to assets:
… (7)
Shows the income obtained based on the resources invested. It is a measure of how much is entered by invested weight in the system. This value should be the highest possible and is compared to its historical values.
2. Profit margin:
… (8)
Profits constitute a part of sales since they are obtained by subtracting from these the costs associated with the process and other expenses, this relationship expresses that part of sales represent profits, and this value should represent the majority.
3. Return on investment:
… (9)
It indicates to what extent the invested resources are being recovered. A low value would indicate that this recovery is slow and vice versa.
All these reasons are valued in an integral way to determine the aspects that are holding back this activity.
| Elements | U / M | Plan | Real | Deviation |
| Material Expense | ||||
| Salary Expense | ||||
| Depreciation | ||||
| Other expenses |
2.1.6 Analysis of indicators of economic efficiency.
The analysis of the indicators of economic efficiency is carried out with the aim of knowing their behavior and evaluating their dynamics. For this, it is necessary to rely on the review of documents related to the economic activity of the system: economic balance of the period, results of economic indicators, etc. Their evaluation is carried out taking into account their growth trend and the deviations obtained from the plan and the previous period.
To carry out this analysis, we will start with the calculation of profits based on the following formula:
… (10)
The result of this indicator will be determined by the behavior of income and costs. If there were deviations in total expenses, these would be caused by:
- variations in production or service costs; variations in expenses outside the process.
The greatest weight of total expenses falls on production costs, so any deviation in their value would be associated with them. The cost of production is analyzed as follows:
- global behavior of the cost of production: the real value is compared with the plan and the deviation is determined; behavior by elements: the cost of production by its nature would be associated with the elements of the process (objects, means, force) through of the expense of materials, expense of salary, depreciation and other expenses, for which it would be determined to what extent each of these elements influenced its total value, considering:
To analyze the deviations of the expenditure of materials, we proceed to evaluate whether it constitutes an economy or an expense through the following expression:
Where: ESMCP Þ economy or material overspending in the cost of production.
ESMI Þ economy or surcharge of indirect materials;
ESMD Þ economy or direct material overspending;
GMIR real actual indirect material expense;
GMIP Þ indirect materials expense plan;
GMDR real actual direct materials expenditure;
GMDP Þ direct materials expenditure plan;
ICP Þ plan compliance index.
If a positive value is obtained, it would indicate that there has been an overspending in the expense of materials and its behavior is unfavorable for the cost of production; if it is negative, it would indicate savings. If there is an overspending in the expense of materials, this could be caused by:
- variations in quantity consumed (VQ); variations in quantities supplied.
Another element that can be analyzed is the behavior of depreciation, if there are any deviations in depreciation, they would be due to variations in the value of productive fixed assets, so it will be analyzed how it has varied:
- its structure: defining which fixed assets varied, its composition: analyzing what percent of fixed assets are productive.
It should be observed in both cases that the increase occurs in those assets related to the process as well as the greatest weight is obtained by the productive fixed assets.
The yield is analyzed whether or not there are variations in the depreciation value. An increase in the value of productive fixed assets must correspond with an increase in their yield. Otherwise, a depreciation expense would be incurred without a productive support, which would have an unfavorable effect on the cost of production.
In addition, the behavior of other indicators such as: productivity, salary fund, average salary, etc. can be analyzed.
Performance dynamics is nothing more than the possibility of the process to systematically increase its efficiency; it can be evaluated by checking the economic efficiency results achieved with those of the same period of the previous year, taking into account the tendency that it should be to decrease, while those that characterize productivity should tend to increase.
2.1.7 Value Accounting.
Although some aspects of the financial sphere to which Goldratt refers in the TOC are implicit in the previous indicators, it is necessary to emphasize those that he defines as optimal for evaluating business performance:
Troughput is the speed that the system generates money through sales; inventory is all the money that the system has invested in buying things that it intends to sell; operating expense is all the money the system spends to transform inventory into throughput. As global indicators it defines net profit, the amount of money that the company retains after fulfilling its obligations; ROI, comparison between the money earned in relation to the money invested and cash flow as real availability of money that the company has deducted from the inflows and outflows of cash.
If throughput increases and inventories and operating expenses are not changed unfavorably, net profit, return on invested capital and cash flow increase; The same occurs if operating expenses decrease and throughput and inventories are not unfavorably modified; 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 is affected, with the net profit remaining unchanged. Regardless of the fulfillment of these situations, we can say that the company is heading towards the Goal.
2.2 Quantify the long-term objectives of the organization.
In order to quantify the long-term objectives of the organization, it is necessary to carry out strategic planning. In which the mission statement is of vital importance.
The mission of an organization is its reason for being, the goal that mobilizes its energies and capabilities. It is the basis for procuring a unity of purpose in leaders and workers in order to develop a sense of belonging. It is the most significant contribution to society. Without the clear definition of the mission, no organization can progress.
A mission statement is a brief description of the greater purpose, the broadest reason that justifies the organization's existence, as well as the support, time, and resources attached to it. From the above it follows that the purpose of a mission is not to expose specific purposes, but to give a general direction, a philosophy that motivates and serves as a guide to the development of the entity.
Every organization has a double mission: one economic and the other social, depending, logically, the second on the first. While the economic mission refers to the critical need to be profitable, the social mission refers to both non-specific aspects such as generating employment and developing professionals, as well as specific aspects depending on the sector and the activity to which it is dedicated: teaching, ensuring, etc.
It must meet certain characteristics:
- Express the service provided by the organization, not the product it sells; It must be directed at developing and promoting positive values in the members of the organization; Oriented towards the outside of the organization, towards the needs of society in general and of the individuals; Long-term future oriented, let alone past. They not only respond to changes, but must promote them; Have credibility, both for the components of the organization and for those who receive the service. Everyone must know, understand and share the mission; be simple, clear and direct. Excessively long missions, full of ideas, beautiful purposes, and beautiful words tend not to work; contain originality. Something different has to be done, better,that distinguishes us and fills us with pride and receives recognition from the people we serve; Being unique. Clarify the social assignment assigned to the organization that differentiates it from any other, although it must be broad enough so that it can be broken down into several concrete and measurable objectives that lead us to fulfill it; Have some intangible and ambitious content but must be related to practical, specific and achievable results. It is better to achieve what is humanly possible, than to try to achieve the ideally desirable; to be constantly reviewed, at least every two or three years, and if necessary, updated and redefined. No human institution is eternal, they all change over time, and even though the mission may be eternal, the particular goals may change.
The mission aims to:
- Prevent changes that will have a profound influence on the organization; Provide employees, customers and others, an identity and an understanding of growth units; Provide a vehicle to generate and project strategic options; Develop positive values in the members of the organization that facilitates the fulfillment of the tasks.
As the mission is the most important step in the strategic planning of a company, it is necessary to strictly comply with the process designed for its preparation, which consists of the following steps:
- Initiation and attention by senior management; Participation and commitment of other levels of management and worker representatives; Preparation of the team in its conceptualization; Preparation of the expression of the mission; Review and feedback; Approval and commitment.
Once the mission of the organization is defined, it is of great importance to make a vision statement, as this is a brief philosophical representation of how your clients, employees, managers and other important people want to see it. It is designed to inspire and motivate those who have a strong interest in the future of the company.
The vision is a set of values and the definition of an ideal desired state to be achieved. For its correct formulation it is necessary to carry out one:
- Evaluation of the information obtained in the strategic analysis; Definition and validation of the vision; Feedback and fixation: here it will be checked if it is compatible with the defined mission, if it really contributes to its materialization and if its achievement is in the hands of the organization.
Main insufficiencies that may arise in determining a vision:
- Define a vision foreign to the mission, it is necessary after the vision is generated to make it compatible with the mission; Insist on figures when they do not appear, the fundamental thing can be qualitative; Develop processes of idea generation without feedback and adjustment; Make excessive emphasis on elements external, move from what you can to what you want; establish a vision without having performed an analysis of the relationships between internal and external factors.
Once the definition of the vision is completed, the strategic diagnosis is carried out, in which two parallel analyzes are carried out that will jointly allow an evaluation of the current and potential situation of the company in relation to its environment.
To define the external strategic position of the organization, an analysis of the micro and macro environment is carried out, where it is determined whether the factors that influence it are manifested in the form of threats or opportunities.
Threats are environmental factors that cannot be prevented, with their influence affecting the operation of the system and hindering or preventing the fulfillment of the mission.
For their part, opportunities are factors that manifest themselves in the environment, represent advantages for the organization and it is possible to take advantage of them conveniently by acting in that direction.
Based on the definition of these factors, the external factors evaluation matrix is prepared.
Then the internal diagnosis of the organization is carried out, which aims to identify and evaluate the internal capacities of the organization, that is, its main strengths and weaknesses.
Strengths are key internal factors that favor the fulfillment of the mission, weaknesses are the key internal factors that hinder the fulfillment of the mission.
Once these factors have been analyzed, the evaluation matrix of the internal factors is carried out to determine the degree of intensity they have and thus define the internal strategic position of the organization.
For the realization of these matrices, the factors previously analyzed must be listed and the classification must be given according to the following criteria:
- strength and most important opportunity => 4 strength and less important opportunity => 3 weakness and less important threat> = 2 weakness and more important threat> = 1
Then a weight is made to these factors, the sum of which must be equal to 1. The weight is multiplied by the classification of each of these factors. Finally, the total sum of this multiplication is determined, resulting in the internal strategic position. and external to the organization. If the result is less than 2.5, the organization is faced with a weak or threatening situation; if, on the contrary, it is greater than this value, the situation is strong or opportunistic.
Once this analysis is done, the SWOT matrix is built. In which all the factors that in the MEFE and MEFI matrices obtained scores of 1 and 4 are listed. Then an interaction is performed between the quadrants and their points are totaled. The quadrant with the highest score will be the one in which the entity is located.
Stage II. Logistics system analysis.
In the present stage, the entire logistics system is diagnosed to determine the restrictions that it may present.
Goals:
- detect the existing reserves in each of its links; determine the restrictions that prevent the achievement of the proposed objectives.
At this stage, a characterization of each of the links in the logistics chain will be carried out, determining their potential from the use of different attributes and indicators.
Chores:
2.3 Identify the subsystems that make up the analyzed logistics system.
Logistics is about the movement and supply in industrial production and service processes of the necessary items, in the right quantities, at the right time and in the right place. Starting from five basic functions that are carried out in organizations: supply management, process management, physical distribution, integrated planning and quality assurance.
Considering in the analysis of each function the requirements that human resource management imposes on the activity and at the same time the requirements that this management currently imposes on organizations.
Logistics is integrative and systemic. To clarify its premises and determining foundations, mission, components, environment, integrators and evaluators, it is necessary to analyze the logistics function, according to the order and content of the system approach.
Taking into account that companies have their particularities and that each one weighs the logistics subsystems according to their mission, at this stage tools are provided to analyze the components of the logistics chain of the system, as well as the subsystems that the authors consider basic for the fulfillment of the service to be provided.
2.3.1 Preparation of the Logistic Map
The logistics map of the entity under study should be drawn up to graphically visualize the set of interactions and the relationship between links in the logistics chain and of these with the other functions of the organization. To carry out the aforementioned map, it is convenient to conceptualize the company and the logistics system in a general way for a better understanding of the proposed methodology.
2.4 Analysis of Clients.
In every service process the client stands out as a fundamental element, this means that the service must satisfy their needs and management is in charge of managing their quality, as the maximum driving force for the success of the organization, involving all the members of this, from the manager to the last person, in an overwhelming philosophy, in a way of doing business, of carrying out tasks and of obtaining results keeping in mind that if there is a good service perceived by customers, this will give a vote in favor, which will translate into profit; for this reason, the importance of knowing the degree of customer satisfaction and in what situation is the level of service in the judgment of customers.
2.4.1 Calculation of the service level.
For this analysis, it is necessary to know the measurement of the Degree of Customer Satisfaction. It depends firstly on the design of the service provided, which must be in accordance with the attributes that he values of it and secondly place, that there is agreement between the service performed and the design specifications. Normally, organizations pay more attention to this last aspect, forgetting to check and poll the customer's opinion about the service's own design; Although the service specifications are met, there may be customers with a certain degree of dissatisfaction.
To measure customer satisfaction from the service design, the following lines can be included: product characteristics (content, color, appearance, smell, taste, variety, temperature, presentation, etc.); delivery time (period between request and delivery or provision of the service); lots or minimum quantity to be served or dispatched; attention and treatment.
With these attributes (making them specific for departments and services), instruments for measuring and collecting information should be designed to evaluate the perception and expectation of the client in order to consider them in the design or redesign of the service. In this sense, proceed as follows:
- Establish and validate with the client the attributes of the service; Weight with the clients the attributes to be valued; Define the scale with which the client will value each attribute of the service; Assign a numerical value to each level of satisfaction to quantify in a single indicator the degree of satisfaction; Proceed to collect, process and develop the information according to the problems or deviations in this or another service or indicator, the steps for continuous improvement.
To complement the analysis of customer satisfaction, the external customer satisfaction index is calculated, designed by Marcia Noda for service units.
… (14)
This index aims to maximize customer satisfaction as a result of excellence in the services offered. To measure this, different instruments can be used to collect the criteria of the clients: direct observation, interview, repeat visits and surveys (qualitative and quantitative).
To perform this calculation using the survey, it is necessary to determine the sample size in this case for a finite population of size N, from the following expression:
As many surveys as the size of the population will be applied and from these the current state (Ea) of the customer satisfaction indicator will be determined, which must be compared with the desired state of the satisfaction index that the entity has set itself to achieve.
The level of service depends on the design of the logistics system and its operation.
Service Level = f (design of the logistics system, operation of the logistics system).
The components of customer service can be:
- product reliability, availability, attitude, product quality.
The level of service is classified into:
- offered; provided; of perception.
Another way of expressing the service level (Ns) is through the system reliability (Fs), which can be expressed by the following expression:
… (16)
Where: Þ production;
n Þ quantity sampled.
2.5 Analysis of the distribution subsystem.
Although this subsystem is not the most important in most service companies, the authors consider that it is necessary to evaluate its conditions, since restrictions may be found in some of the distribution channels that limit the full operation of the entity..
As essential objectives of the distribution subsystem, the following can be mentioned:
- Reach the client on time and in the stipulated way. Minimize distribution costs, maximizing profit. Minimize the total cost of physical distribution until delivery to the client, for greater profitability.
The output of the service to the final customer in many organizations has transport as its main actor, however, in others, it is in Human Resources that this task rests, so these must be carefully analyzed.
2.6 Analysis of the Transformation Subsystem.
This subsystem assumes responsibility for the transformation of the materials acquired through the supply process into products and / or services for their subsequent distribution. Its main objectives are:
- Provide the products to the distribution process under the conditions of quality, quantity and deadlines required. Minimize the cost of production seeking the maximum benefit. Minimize the overall cost of production until the time of moving to distribution, obtaining maximum profitability.
2.6.1 Calculation of Process Capabilities.
To calculate the capacities, the following steps must be carried out:
- define the type of production (homogeneous or heterogeneous); define the nomenclature of products to consider; definition of the processes to be analyzed, as well as the equipment park for each one; determination of the time-consuming regulations; definition of the work regime determine the time funds available.
Based on the quantities of equipment available, the statutory work regime and the time allocated to technological and / or organizational requirements, the time fund available for each homogeneous group of equipment is defined.
Total Productive Time Fund (FPT).
It is the maximum number of hours possible to work in the period analyzed. It is defined in different ways according to the type of the manufacturing process of the system.
For continuous process companies it corresponds to 365 days a year for 24 hours a day
(365 days a day * 24 hours a day = 8760 hours a day). … (17)
For non-continuous process companies it corresponds to 280 days of the year for 24 hours a day, discounts are taken on non-working Saturdays, Sundays and holidays, (280 d / a * 24 h / d = 6720 h / a). … (18)
Technological Requirements Time Fund (FRT).
It is the amount of time that is used by the company in the development of activities required by the technological characteristics of the manufacturing process that requires the stop of the manufacturing flow and it is mandatory to execute to guarantee the normal operation of the company's technological process.
Potential Productive Time Fund (FPP).
It is the maximum possible amount of working time for the company, after considering the times that due to technological factors cannot be used. This time fund is used in the calculation of the indicator of potential productive capacity and its utilization.
… (19)
Labor Regime Fund (FRL)
It is the time not used by the company as there are differences between the existing work regime in the company and the one established according to the characteristics of the manufacturing process; which served as the basis for calculating the total productive time fund. In this time it is reflected:
- time not used because there are differences between the number of hours to work daily and the 24 hours a day defined for the calculation of the total productive time fund; time not used because the company does not work in a massive vacation system. When this time is used for maintenance work, it is not included; time not used because the company does not work the total work shift, that is, the time consumed in the workers' snack. It is taken into account when the technological process and all those that are not included in the work standard are paralyzed.
Time Fund for Other Causes (FOC)
It is the one that cannot be included in the other non-usable times and is caused by organizational problems of the company and on which the group of workers cannot influence its decrease. This time includes the accidental breakage of the equipment due to the lack of correct preventive maintenance, the lack of electrical energy, etc. Its calculation is made from statistical data, using the behavior of previous productions.
Available Productive Time Fund (FPD).
For heterogeneous productions the available productive fund is calculated:
…(twenty)
Where:
d Þ working days per year;
h Þ hours per day worked;
shifts a day;
α Þ loss of time due to maintenance and other causes.
7. calculation of capacity.
2.6.2 Calculation of Possible Production.
In each process it is possible to reach a maximum level of utilization, which depends on the stability with which the process works. In turn, stability is given by the reliability of the process and of the existing reserves.
For heterogeneous productions the expression to use is the following:
…(twenty-one)
Where:
CPD disponible available productive capacity;
Red Þ regulated performance of each process.
In service units Roj = AJL.
2.7 Provisioning.
This subsystem is made up of several functions: Purchasing, which is in charge of evaluating and selecting suppliers, as well as the administration of purchases and Storage, which is in charge of inventory control and warehouse administration.
The objectives of the provisioning subsystem can be summarized as:
- Have the necessary supplies to respond to the needs of the clients. Minimize the acquisition cost to obtain the maximum benefit. Minimize the integral cost of supply (operating expenses) to obtain the maximum profitability.
2.7.1 Analysis of the Warehouses.
Immense quantities of products and supplies necessary to develop the service process are permanently in storage and awaiting further processing, sale or use.
The feasible diagnostic techniques to apply to warehouses are based on the calculation and comparative analysis of compliance with indicators that evaluate the performance of this link in the logistics chain, they are:
to. Size or volumetric capacity (Cv). Its calculation is carried out as follows:
… (22)
Where:
L = length of the warehouse (in meters);
A = width of the warehouse (in meters);
H = warehouse height (in meters).
With the support of the previous analysis, a plant distribution can be carried out allowing the warehouse capacity to be determined in tons for food products and in cubic meters for industrial products.
b. Use of warehouse space in areas, height and volume.
Area utilization coefficient (Kat).
…(2. 3)
… (24)
Where: Au útil useful warehouse area (area occupied by the shelves or pallets in the storage itself, excluding aisles, is expressed in m2);
At Þ total warehouse area, expressed in m2;
The length of the warehouse (in meters);
Ba Þ width of the warehouse (in meters).
In the country the value of Kat = 60% can be considered as very good.
Height utilization coefficient (Kh).
… (25)
Where: Ha Þ average height of the pallets of materials, products and storage shelves (in meters);
Hu útil useful height of the warehouse (it is the prop of the warehouse, which subtracts the spaces occupied by cranes if they exist, the roof structure and a meter that must be the minimum separation between the roof and the pallets or shelves.
The maximum achievable Kh values are around 70%.
Volume utilization coefficient (Kv).
… (26)
… (27)
Where:
Vu útil useful storage volume (m3);
Vt Þ total storage volume (m3).
The use of 30 to 40% of the available cubic space is considered efficient.
Static storage capacity (Qec). It is the maximum quantity of products that can be stored at any given time in a warehouse or warehouse base according to existing technology. Static storage capacity is usually measured in tons (static load capacity) and in some cases is expressed in cubic meters.
The static load capacity (measured in tons) is calculated by multiplying the average load per m2 by the useful area.
Qec = CP * Au… (28)
Where:
Qec: It is the static load capacity.
CP: It is the average load per m2.
Au: It is the useful area.
The static capacity measured in cubic meters is calculated by multiplying the useful volume by the use in the storage media and by a coefficient that relates the possible material volume to be stored in a certain useful volume for each storage technology.
Qev = Vu * Ama * Kv… (29)
Where:
Qev: It is the static capacity measured in cubic meters.
Vu: It is the useful volume.
Ama: It is the coefficient of use in the media for storage.
Kv: It is the coefficient that relates the possible material volume to be stored in a certain useful volume for each storage technology.
Dynamic Storage Capacity (Qdc). It is the maximum quantity of products that can be stored in a given period of time (usually in a year) in a warehouse or warehouse base, according to the existing storage technology and the level of rotation executed or planned.
Dynamic storage capacity is usually measured in tons (dynamic load capacity) and in some cases is expressed in cubic meters (volumetric dynamic capacity).
The dynamic load capacity (measured in tons) is calculated by multiplying the average load per square meter, by the useful area, by the number of rotations of the products, or also by multiplying the static load capacity, by the number of rotations of the products, usually in one year.
Qdc = Qec * n… (30)
Where:
Qdc: It is the dynamic load capacity.
Qec: It is the static load capacity.
n: It is the coefficient of rotation.
The dynamic capacity measured in cubic meters is calculated by multiplying the static capacity measured in cubic meters by the number of rotations of the products, usually in one year.
Qdv = Qev * n… (31)
Where:
Qdv: It is the dynamic capacity measured in cubic meters.
Qev: It is the static capacity measured in cubic meters.
n: It is the coefficient of rotation.
Although there are other indicators that allow us to assess the efficiency of work in warehouses, the most representative ones have been shown.
2.7.1.1 Replenishment system used.
Replenishment is the function in charge of managing the materials necessary to carry out a production or provide a service. For independent demand generated as a result of the decisions of many actors outside the logistics chain (customers or consumers) they can be classified into two large groups:
- Continuous review method or fixed amount of replenishment (Q system): Q systems are characterized by checking the stock level continuously or every time an extraction is performed, against the predetermined level which is the reorder or order level. When the stocks fall below this level, the order is immediately placed and this is always of the same magnitude, that is, the one that has been considered the most convenient. Periodic review method or reorder canned cycle (P system): Characteristics of this system is offered by the fact that the situation of each item is reviewed at regular intervals of time and that the quantity to be ordered varies from period to period and must be of such a size that it achieves the target inventory. Article review intervals can be weekly,biweekly, monthly, or perhaps less frequent.
The JIT (Just In Time) model is also used with satisfactory results. The Just in Time more than a production system is an inventory system, where its goal is to eliminate all waste. Waste is generally defined as anything other than the absolute minimum of material, machine and labor resources required to increase the added value of the product or service.
The Just in Time needs major modifications to the traditional methods of sourcing supplies. Suppliers are chosen with whom special contractual arrangements are made for small orders. These orders are delivered at the exact times when the user needs them and in small quantities that are sufficient for very short periods.
2.7.2 Analysis of Suppliers.
The raw materials and materials supplied by the different suppliers naturally influence the quality of the service, but the relationships with the suppliers go beyond the quality of the products they supply. Its economic stability, its prices, its ability to meet delivery deadlines and other parameters influence the entire set of relationships to achieve the balance that optimizes the overall relationship.
The purpose of the supplier relationship is to enable the buyer to gain confidence in the use of the goods. For traditional products, this objective is based on being able to accept the product without the need for inbound inspection, subsequent modifications or touch-ups. As for modern products, the objective is to trust the supplier as if it were a department of the company itself.
Various sources of supply should be used, since using just one can reduce your competitiveness both in terms of quality, cost and services.
Based on the knowledge of the number of suppliers per assortment, the indicators for their selection must be defined, among which can be used are:
1. Possibilities or financial capacity to purchase (payment facilities).
With positive buyer-supplier relationships, communication is expanded and thus the probability that the supplier changes from a defensive posture to an attitude of constructive proposals in financial exchanges.
2. Price: Undoubtedly, the best supplier taking into account only the price is the one that provides the lowest, but one way of comparing is to calculate for each supplier an indicator resulting from dividing the lowest price offered and the one specifically proposed by the supplier.
3. Quality: A convenient and quick way to measure the quality of products from a certain supplier is through the number of defective products in the total shipped or through the number of accepted products in the total shipped.
4. Service: It is mainly reflected in the delivery time of the order, measuring it by the number of delays that occurred in a certain management period or the number of orders delivered on time in said period.
5. Timing of supplies.
This indicator allows you to analyze whether suppliers guarantee the arrival of supplies to the company in sufficient quantities and at the right time to meet the objectives set.
… (32)
Where: Spj Þ supply plan that must arrive in period j;
Srj Þ actual supply that must arrive in period j;
Inv.Þ reserves or stocks from the previous period.
6. Global compliance of supplies.
7. Attention to claims.
It is usual that each of these indicators can be calculated and expressed in percent, proposing the following quantitative expression that allows evaluating suppliers:
… (33)
Where:
I: is the indicators to evaluate.
Pi: is the weighting of the same.
2.8 Analysis of Human Resources.
The relationship established between internal clients and external clients is of fundamental importance in service companies due to the role that the human factor assumes in them, which transmits external clients their own satisfaction, and it is essential to have a strength trained, motivated and with a high vocation for service, constantly monitored to undertake actions that avoid deviations from the desired standards in their performance. Human Resources represent a fundamental link in the logistics chain and its correct administration constitutes a fundamental step on the road to La Meta.
2.9 Analysis of the existing information system.
This analysis is carried out with the aim of determining whether the information flow of the company under study is being rationally treated, within which the following elements must be taken into account:
- Issuance and monitoring of orders. Information Management. Planning and Control.
As main ideas of information systems, it must be borne in mind that the information processed must be relevant, timely, accurate and shared among the levels at which it is responsible to avoid loss of time and provide efficiency in the decision-making process.
2.10 Determination of existing problems in the logistics chain.
At the end of each of the previous tasks, an analysis will be made of the existing problems that constitute the reserves and restrictions of the system.
Stage III. Solution strategy.
This stage and the next are in charge of proposing and following up on the solution strategies given to the problems detected.
Objective:
Design a solution project that allows the entity to eliminate the detected restrictions and thereby increase the quality of services and customer satisfaction.
Chores:
- Formulation of alternatives for improvement: alternatives for change in the current system and its component parts should be formulated to eliminate the detected restrictions and improve the operation of the system; Selection of the best alternative: the alternative that best contributes to satisfaction of the objectives of the logistics system, also ensuring the efficiency of the operation of the system; Projection of the solution: we will proceed to project the measures, methods and procedures that the selected alternative implies, with a view to enabling its systematization.
Stage IV. Projection of solutions.
Objective:
Define the conditions to be created and the sequence of tasks to implement the projected solutions.
Chores:
1. Preparation of the implementation program.
The implementation program constitutes the set of tasks to be carried out in an orderly manner in the planned time to put the company in the required conditions. The following aspects are included in this program:
- The resources necessary to implement the project: technical means, materials, workforce, etc.; Change of qualities of the resources: qualification of the workforce, change of supply, installation of new equipment, etc.; Improvement of conditions of the company: modification in the distribution in plant of the organizational structure of direction, etc., Define the terms of fulfillment of each task, its managers and executors.
2. Application and monitoring.
This task is of great importance, since it is where the change (improvement) can materialize and achieve the elimination of the restrictions detected to meet the objectives of the system.
Techniques:
To apply this methodology it is necessary to use different techniques which will be explained briefly.
- Direct Observation: it is a primary method of gathering information about the objective to be studied. It consists of capturing objective reality directly through a given procedure. Document Study: consists of searching for and obtaining those documents that contain information necessary for the study, which may be internal or external to the company. Interview: it is a structured technique to collect information from individuals and groups with a specific purpose. The interview will take into account the interviewee's speech, gestures, expressions, reflections, etc. Survey: Techniques of Economic Analysis: the role of economic analysis is to detect ways to achieve the activity of the Production System o Service is more efficient within the framework of the demands imposed by the environment,since through it are detected: the internal reserves of the Production or Service System, the causes of the deviations of the analyzed phenomenon and eliminate the deficiencies that have caused the negative deviations. System approach: It is one of the most used methods in the activity of organization, since it makes it possible to consider the process in its character as a system that is understood as such, to the interdependent set of elements and processes whose quality is not the mechanical sum of its parts. sections of group work with specialized personnel. of agreement of Kendall: this method consists of requesting from each selected expert his criteria about the ranking according to the degree of importance that he attaches to each one of the characteristics to be selected. General Model of Organization. Photography. Product Engineering.
Conclusions
The model and the procedure proposed due to the lack of these for the application of TOC lead to the following conclusions:
- The developed model coherently integrates all the elements that determine the operation of the logistics chain and thereby facilitates the implementation of TOC as a management philosophy. The proposed procedure detects and manages the limitations of the system regardless of where it is located. find allowing the gradual and sustained performance of the organization which shows its applicability. Specific procedures are proposed to:
- The characterization of the system under study. The Calculation of Productive Capacities. The detection of physical restrictions. The continuous elevation of restrictions.
These make possible the study of the analyzed systems and the application of the general procedure.
- It is possible to manage the logistics chain through the TOC following the logical steps that are proposed throughout the chapter.
Bibliography
- Acevedo Suárez, José A.. Classification of the Types of Production Systems / Acevedo Suárez, José A. and Urquiza, Ana Julia /. In Industrial Engineering Magazine. Havana, 1998. Volume IX, No. 2. 184 p. Acevedo Suárez, José A.. Capacity Management in Logistics Systems. Havana City: ISPJAE Editorial, 1996. 20 p.Arana Pérez, Pilar. Criteria to Technically and Economically Evaluate the Application of Production Systems. In Business Studies Magazine. Spain, 1994. No. 85. 39 p.Arbones Malisani, Eduardo A.. Business Logistics. Editoral Boxareu Marcombo, 1990. 157 p.Ballow, Ronald H.. Business Logistics. Control and Planning. Havana: Editorial Científico Técnica, 1985. Conde Hernández, Natividad Lourdes. Logistics as a Partner in Business Management. In Revista Metánica 88. Havana, January 1998.No.3 40 p. Applied Logistics. Magazine of the Cuban society of Logistics. No. 1, May, 1996. 44 p.
