Process is any sequence of steps, tasks or activities that lead to a certain product, which is the objective of said process.
The processes can be: Production, when the result is an industrial good, services, when that result is an intangible good, such as health or transport, administrative, whose purpose is an administrative act such as a purchase, a collection, a payment or that leads to produce or modify information.
Each of them are detailed below:
processes-and-productivityProduction processes
During the production of a good or service, the term process designates both manual tasks, systems that coordinate workers and machines; such as automated processes, in which the worker plays an indirect or controlling role.
Manual jobs generally use certain mechanical aids and are responsible for a significant proportion of productive activities. The design of these manual activities and their relationship with the phases of operation and control of the machines that are used, corresponds to the area of Industrial Engineering, which deals with the design of working methods.
Manual activities, or the operation of machines, are frequent in component assembly or assembly work, in administrative activities (offices), in supermarkets, hospitals, etc.
There are production processes that have a very complex technological base, such as the metal-working industries (metal-mechanical branch), the wood industry, the plastics industry, and the chemical industry, whose characteristics can be found in specialized texts.
The purpose of a process is to produce transformations. Something happens that somehow produces changes in the object on which you are working. These transformations can produce chemical changes (chemical processes), alter the shape or structure (mechanical processes), remove or add parts or pieces (assembly processes), alter the location of the object being processed (transport) or verify the accuracy (inspection and quality control). These processes are described below:
Chemical processes
They are typical of the oil and plastics industry, the production of steel, aluminum, etc.
Given its complexity, the description of nature and its scope is beyond this chapter; However, it can be noted, in general terms, that it is always possible to study its stages according to the operations or transformations that occur (such as chemical reactions, heat transfers, filtering, absorption, etc.).
From an industrial point of view, these processes can be discontinuous or continuous.
An example of the first case is that of the steelworks in the iron industry, in which molten iron is produced from ore, coke and limestone; These inputs are introduced in alternating layers in the blast furnace, into which hot air is injected under pressure to maintain the combustion of the coke. As it burns, the coke absorbs the oxygen from the mineral and the limestone absorbs impurities; thus, the charge descends, increasing its temperature until the iron melts and is concentrated at the bottom of the furnace from where it is periodically extracted (cast) to obtain pig iron in ingots.
An example of chemical processes of a continuous type is the case of the oil industry, where the raw material (crude oil) is subjected to a series of heat transfer operations, pressure, mixing, transport, etc., and the product leaves continuously extracting selectively.
Processes that change shape or structure
They are typical of the metal processing and machining industry, the wood industry and the molding and forming of plastics. Below are some notes on the metalworking industry and its characteristics, which is the most representative of this type of process.
The metal-mechanical industries are subdivided into heavy and light. Examples of the former are some of those that carry out primary forming operations, such as lamination, from which metal bars, plates or profiles are obtained.
A special case in the metallurgical industry is foundry, in which, by liquefying metals at high temperatures and then molding them in sand molds or in dies, they are given the desired shape, which may or may not require other operations.
Another special formation process is hammer forging, which is a mechanical process in which the iron is heated to red, a condition in which it is more malleable, forming it by means of blows, and finally tempering it by sudden cooling in water or oil.. Mechanical forging does the same with large automatic "pylon" hammers.
Stamping is typically part of light metallurgy, and consists of a combined punch, push, and cut operation that shapes a part by cutting it from thin sheet metal. The machine of. ….. it is the rocker arm and in it a great variety of pieces are produced, such as washers or ……. The stamping can also be "pressed" then using hydraulic presses, instead of rockers.
The typical operations of the metal - mechanical, light are those that are carried out with the machine - tools, basically the lathe, the filing machine and the brush, the grinding machine, the milling machine and the gear formers. These tools allow you to generate cylindrical, flat, curved and complex surfaces; and perforations.
To transform the metal, these machines mainly use two means: a “tool” made of an extremely hard metal or a “stone” that is also very hard (carborundum), which grinds the metal.
The lathe is a rotating mechanism that clamps the part to be worked, with a sliding tool, in which surfaces of revolution are produced. The filing machine is a mechanism that moves forward and backward, in which the tool attached to it, works a piece that slides in a transverse direction. Produces flat surfaces. The brush is the same, only that the relative movements of the tool and part are reversed.
The grinder consists of a high-speed rotating stone that works a rotating or sliding metal part (producing surfaces of revolution or flat).
The bur is a rotating tool like a dentist's lathe, with which excavations are produced.
The formers or creators of gears are machines in which a very hard metal gear is wearing down a cylindrical metal part to make it, gradually, mesh with it.
Assembly processes
Some of the processes used to join parts and pieces are welding, riveting, screwing and gluing. These processes are common in the automotive, electronics, household appliances and some related to the electromechanical industry.
It can be affirmed that automation has not reached the assembly operations, except in the large electronics industry, with the development and application of printed circuits, which in any case are a small proportion of the total assembly of a device.
Much of the analysis of assembly operations depends on the study of times and movements and the relationships between the worker and his tools, as seen above.
Service processes
They are those not directly productive, or not related to industrial production. This is the case of transport, health services, municipal or home cleaning and cleaning, housework, etc.
In all these activities there is a process since there is a sequence of steps that lead to the end sought. Transporting, for example, involves loading and unloading what is transported. Cleaning a house or city or cooking a meal also have a sequence of steps that can be described as a process, much like production processes.
Administrative procedures
It is a whole sequence of steps that lead to producing, recording, preserving or modifying information.
When an object is purchased in a store, the ticket serves, for example, among other things, to record low inventory and sales volume, to collect the amount from the customer and to control the cash register. There are much more complex administrative processes, which require the use of a very large number of papers (documents or forms) that go through a long series of registration, calculation, control and filing steps.
In large companies, the volume of these is so large that they are processed by computers that use the basic information of a document for a series of statistics, calculations, and to produce other documents that were normally prepared by hand. Such is the case of a food producing company; when one of your vendors sends an order as required by a warehouseman. The computer, based on that single role, does the following operations:
Orders the warehouse to deliver the merchandise to the expedition.
Compile, with this and other orders, the list of merchandise that a certain trucker will carry on a given date.
Issues the invoice in which the customer will be charged and the receipt that will be granted when paying.
Make sales statistics by customer, by seller, by product sold, by geographical area, etc.
Make the accounting document called "Sales Book".
Need to streamline processes
It is essential to analyze and streamline processes, among others, for the following reasons:
a) Any human activity, aided or not by mechanical means, can be described as a process. This being a sequence of steps that lead to an objective or result, it is essential to study each process to achieve the most economical sequence of steps.
b) Using the most suitable machine tool for the volume and type of work, the best will be achieved at the minimum cost.
c) By studying and simplifying the service processes, these will be obtained in a better, faster and cheaper way. This can be applied to a comprehensive study of urban transport or the distribution of elements and appliances in a kitchen.
d) Administrative rationalization will speed up the process of producing information, will reduce the number of documents and bureaucracy and will achieve its objective more quickly and efficiently and at the lowest cost.
Description and analysis of the processes
Generalities
In order to describe the processes, it is necessary to record them, in such a way that omissions or errors are not made, and also that the presentation can be understood by all the entities for which it has been made.
Whenever possible, the observation should be direct, and to record it, it is necessary to make use of conventional symbols. The problems involved with direct observation, the degree of fineness required, the flow charts and symbols used to define the different diagrams that are used are analyzed below.
a) Comments on direct observation
Man has a natural tendency to believe that what surrounds him is in a certain way and by registering it in memory in this way, he then has the "certainty" of its truthfulness.
For this reason, whoever wants to "record any situation using the comments and opinions of those who" have been doing the work for years, will incur a series of errors no matter how good the faith of those consulted.
The time during which they are doing it may be a long time, but they will tend to underestimate what they have been fully mechanized in and therefore do without thinking, so that the record that is made in their opinion would not be complete.
The same would happen to anyone who wants to know the details of a process, based on information in a book or a technologist, no matter how good they are. Because in the vast majority of cases, both describe the processes in a "generic" way, omitting secondary aspects or accessories that later, in practice, are essential for the good design of the project.
In the absence of being able to observe directly in a plant as similar as possible to the one that is projected (which is always the best method), you can obtain the information you want from a specialist technologist, provided that you ask correctly and know how to give order and it trains the always numerous disorderly knowledge that any professional who has worked for many years in a certain industrial branch normally possesses.
As the common thing is that a technologist lacks experience in project design, he would tend to emphasize, for example, aspects that are sometimes purely operational (something like that the temperature should not vary by more than half a degree) and omit questions that, although seem (and are) insignificant from the point of view of the process, they are key in the design of the project, as for example that between operation "A" and "B" there is a lot inventory that must be considered in the area of floor of the plant to be projected.
b) Comments on the degree of fineness to record information.
When observing a process or an operation with the aim of recording it, or when trying to describe a process based on verbal information, the question immediately appears about the degree of detail that should be used, for which the following recommendations are useful:
The degree of fineness of the record will be greater the more important the details have to find the solution.
There are different registration techniques, each of which uses a certain degree of fineness. The analyst will choose the one that corresponds to the case, taking as many or as few details as needed.
If what is desired is to describe the plant or section as a whole, a general register is used. If you want to save fractions of time on a task that is repeated hundreds of thousands of times a year, you will need detailed recording. On each occasion there will be a degree of fineness that is the most appropriate, since more detail in the record means more study time, and consequently, higher costs.
Process charts
The simplest way to describe a process is through flow charts or process charts. They consist of graphs in which the operations or fundamental stages of the process are described, indicating the materials that are being incorporated, and the results of each operation. The most commonly used types of graphs are:.
b) - Process flow chart or flow chart. It provides considerably more detail than the general process chart, and uses all five symbols. They refer to man (or machine) and material.
c) - Multiple activity graph. A graph of this type that can be considered as a vertical Gantt chart, is used to show the relationships in time between two or more men, machines or materials.
d) - Simultaneous movement graph (SIMO graph, simoultaneous movement). In this, movements of two or more parts of the body of a worker are registered. They are usually very short-lived movements or micro movements.
Motion graphics
e) - Route graph. In complex situations, it is sometimes confusing to try to use a flow chart, and then journey or journey graphs can be used. in these the number of movements made in a period can be registered.
f) - Flow charts. This shows the workplace and the positions of the various activities, drawn to scale. The five standard symbols are used in it and refer again to man, material or machines.
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