Quality control, as well as testing, depending on the stage of the product life cycle, can be carried out at the production stage (so-called production control), as well as at the operation stage (in other words, operational control). In our article, we will consider the concept and types of product quality control, as well as analyze other thematic aspects.
Category concept
Quality control should be understood as checking the compliance of the qualitative or quantitative characteristics of the process on which the quality of the product depends, or the product itself, to certain technical requirements. The currently existing types of product quality control in the aggregate are the most important component of the production process. It is worth noting that they are aimed primarily at checking the reliability during manufacture,consumption or operation of the product.
The essence of quality control
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Control involves checking products directly at the beginning of the production process and during maintenance. At the same time, in case of deviations from the regulated requirements in terms of quality, it implies the adoption of corrective measures that are aimed at producing a product of good quality, as well as full maintenance during the operation period and absolute satisfaction of consumer requirements.
No control
Product control includes certain measures at the place of its creation, development or at the place of its operation, as a result of which deviations from the norm of the required quality level that have been made can be eliminated by production employees even before the release of defective products or product that does not meet specifications. It is important to keep in mind that insufficient control at the stage of manufacturing a serial product, as a rule, leads to financial problems. It entails unplanned costs.
Whatincluded in quality control?
Before considering the classification of types of product quality control, it is advisable to understand what this category includes. It is important to include the following elements here:
- Incoming control of the quality characteristics of raw materials, main and auxiliary materials, components, semi-finished products, as well as tools that enter the warehouses of the production structure.
- Procedural production control, first of all, over the observance of a certain technological regime. In addition, this paragraph may refer to interoperational acceptance of products.
- Systematic control, first of all, of the condition of machines, equipment, cutting and measuring tools, various measuring instruments, models of weight management and testing equipment, stamps in operation and new devices, production conditions and subsequent transportation of products. It is worth noting that these are not all existing checks.
- Control of prototypes and models.
- Control of the finished product (small units for assembly, subassemblies, parts, assemblies, products, blocks).
Modern definition of quality control
Today known types of product quality control cover all the processes of the product life cycle, from input plan resource control, production controlpreparation and production of a commercial product, as well as the control of the operation of products and ending with the control associated with the storage of products. It is important to note that the control of operation should be attributed to the control of the operation of the equipment. It is necessary to confirm durability, determine reliability, study the nature and nature of random failures.
Under the totality of types of product quality control, as we found out, it is necessary to understand the control of qualitative and quantitative characteristics. In the modern definition of a category, there is an addition that these features are represented by attributes and variables. The measurement of the latter is based on numerical scales of the continuous type. This, for example, length or weight. Attribute evaluation is provided either without measurement in detail (as an example, consider the use of an instrument to test according to the pass-fail principle according to specifications), or in a subjective way (something may or may not have some attribute, for example surface finish good or bad). It should be added that the assessment of the quality of commercial products, if the characteristics are represented precisely by attributes, is called an assessment by an alternative attribute.
Random roots of the measured value can be determined by the influence of numerous, as a rule, almost insignificant factors in the manufacture of a commercial product. It is worth knowing that it is impossible to predict them. This is a change in temperature, defects in materials, conditions of transportation and storage, deviation of the voltage in the network directly from the nominal, and so on.next.
GOST classification
Today, the types and methods of product quality control are classified according to a number of characteristics. All divisions considered in the article fully comply with GOST 16504–81. So, if we take the stage of development and existence of the product as the main parameter, then the types of technical control of product quality are the following varieties:
- production control, which is carried out at the production stage;
- operational control, which is implemented at the stage of operation of marketable products.
Comprehensiveness
According to the completeness of coverage of a commercial product by control, it is customary to distinguish the following types of product quality control at the enterprise:
- Solid, in which all units of marketable products are subject to control.
- Sampling, in which a relatively small number of units of a product are controlled from the entire population.
- Flying, which is carried out suddenly, in other words, at moments unplanned in advance.
- Continuous procedure. This type of product quality control is carried out in relation to liquid and effervescent materials. It fully ensures the continuous flow of information regarding controlled characteristics.
- Periodic, that is, the receipt of information about the controlled features is carried out throughset time parameters.
Total and selective control
Separately, it is advisable to consider such categories as continuous and selective control. The fact is that it is fundamentally important to see the difference. So, continuous (continuous) should be understood as the ultimate version of one hundred percent (comprehensive) control. In other words, in this case, the procedure is implemented in relation to each unit of marketable products. Carrying out this type of technical control of product quality is associated with significant costs. That is why, as a rule, it acts as a proof of the general hypothesis regarding the nature of the change in the random variable that is being controlled.
Under the sampling procedure in accordance with GOST 15895–77, it is necessary to consider periodic sampling for analysis purposes or a periodically performed certain number of measurements of the quality characteristics of commercial products. It is worth knowing that the sample size or the number of measurements should be determined based on the methods of mathematical statistics.
Production process step
In accordance with the stage of the production process, it is customary to distinguish the following types of product quality control: input, operational, acceptance, output and inspection. Consider them in more detail:
- Incoming control of materials, raw materials, components, in other words, the control of the supplier's product that arrives at the customer or consumer and is intended for use at the stage of operation, manufacture or repair of marketable products.
- Operational control of quality characteristics in the manufacturing process of the product to evaluate the technological process with subsequent adjustment, if necessary.
- Acceptance control (not necessarily related to the finished product) is implemented to make decisions regarding the suitability of the goods.
- Output control of the finished product. It is often referred to as the finish line.
- Inspection control should be understood as a procedure that refers to an already inspected product. In this case, a previously discovered marriage is deleted. This type of quality control of catering products or other industries is carried out if it is necessary to check the quality of the work of the technical control department. It is worth noting that in some cases the inspection control is performed by the customer's representatives in order to increase the responsibility of the manufacturer's control structure.
Influence on the object of control
In accordance with the criterion of influence on the object, the following types (methods) of technical control of product quality are distinguished:
- Destructive control procedure, during which the object's suitability for use may be violated.
- Non-destructive testing, according to which the suitability of the object for use is maintained.
Use of controls
Finally, the fifth criterion chosen for the classification of quality control according to GOST is the usemeans of control. In accordance with it, it is customary to distinguish the following types of control procedures:
- measuring control, which is carried out using measuring instruments;
- registration procedure, which is implemented by registering the values of parameters to be controlled, processes or commercial products;
- organoleptic control, according to which the primary information is perceived by the senses;
- under visual control should be understood the organoleptic procedure that is carried out by the organs of vision;
- technical inspection should be considered as control, which is implemented, as a rule, through the senses, and, if necessary, special means (their nomenclature is determined by the relevant documentation).
Final part
So, we have fully considered the varieties, in other words, quality control methods in production. In addition, they touched on those types that in practice go beyond the production process (we are talking about operational control, a mandatory procedure today). It is worth noting that the classification developed in accordance with GOST is quite extensive. It contains five criteria for the formation of a complete and understandable structure of the category under study.
It is worth noting that in the modern world the importance of product quality control is extremely high. This can be explained by the increasing needs of society, the development of new information technologies, the strengtheningcompetition in both domestic and international markets, as well as numerous other factors.
