Control can be defined as "a process by means of which we observe the actual performance and compare it with some standard".
If there is a deviation between the observed performance and the standard performance then it is necessary to take corrective action.
The term "Quality Control" has variety of meanings:
1. Quality control is the process through which we measure the actual quality performance, compare it with the standards and take corrective action if there is a deviation.
2. It is a systematic control of various factors that affect the quality of the product. It depends on: Material, Tools, Machines, type of labor, working conditions, measuring instruments, etc.
3. Quality control can be defined as the entire collection of activities which ensures that the operation will produce the optimum quality products at minimum cost.
4. It can also be defined as the tools, devices or skills through which quality activities are carried out.
5. It is the name of the department which devotes itself full time to quality functions.
6. The procedure for meeting the quality goals is termed as quality control.
7. It is a system, plan or method of approach to the solution of quality problems.
8. As per A.Y. Feigorbaum
Total Quality control is "An effective system for integrating the quality development, quality maintenance and quality improvement efforts of the various groups in an organization, so as to enable production and services at the most economical levels which allow full customer satisfaction."
Steps in Quality Control Program
1. Formulate quality policy.
2. Work out details of product requirements, set the standards (specifications) on the basis of customer’s preference, cost and profit.
3. Select inspection plan and set up procedure for checking.
4. Detect deviations from set standards or specifications.
5. Take corrective action through proper authority and make necessary changes to achieve standards.
6. Decide on salvage method i.e. to decide how the defective parts are disposed of, entire scrap or rework.
7. Co-ordination of quality problems.
8. Developing quality consciousness in the organization. Quality control is not a function of any single department or a person. It is the primary responsibility of any supervisor to turn out work of acceptable quality.
Quality control is one aspect of production planning and control. It is basically concerned with the quality production through regular inspection technique. Quality is a combination of characteristics pertaining to the manufacture of the product and control is the correction in the quality of the product, when the deviations in the product are more than expected. A good quality item is one which conforms to some standard specifications. These specifications are determined by the expectations of consumers and also by the availability and costs of processes and materials.
To most people, quality is variable. It is subjectively judged because it deals with the relative goodness of a product. When a buyer boasts that his house or car is the best, it implies high quality. Quality is thus subjective and vaguely measurable.
In the words of Broom,
"subjective quality refers to degree of goodness of a product and objectively it consists of a set of measurable characteristics for which standard dimensions together with small, allowable departures, up and down, may be prescribed."
All manufacturing processes face a basic difficulty. It is physically impossible to make all items or units exactly alike. There is always variability in the product. With precision manufacturing, the variability may be difficult to see but nevertheless it is there. When variability becomes obvious it results in scraps, re-work and losses, thus adding to the costs.
Objectives of Quality Control
1. Establishment of quality standard: The main objective of quality control is the economical production of a high quality product at the quality level the customer wants. It is basically for eliminating variations in production and in order to have uniformity in production.
2. Locating quality deviations: It is necessary to analyze the trend and extent of quality deviations in a manufacturing process. Such deviations should be explained by statistical techniques when they cannot be attributed to the element of chance.
3. Evaluating methods and processes of production: By evaluating methods and processes of production, quality control helps to take corrective measures to maintain the quality of the product during the process of manufacture.
4. Quick sale of quality goods: Quality control accelerates the sale of the goods by supplying only the quality goods in the market. Consumers also support quality goods.
5. Production of standard quality goods: Quality control aims at manufacturing standard quality products and avoids the production of inferior quality goods. Such standard quality goods give satisfaction to consumers and also create goodwill in the market.
6. Improvement in quality: One objective of quality control is to find out high quality standards and to make constant efforts to reach those standards. Quality control aims at creating quality consciousness at all levels in the Organisation.
Steps in Quality Control Process
1. Devising control over raw materials: The quality of the finished product is determined mostly by the quality of raw materials. It calls for close connection between the raw material purchase department of the company and the vendors. As and when necessary, a resident inspector may be deputed by the Quality Control Department in the vendor's place to see that only goods in accordance with specifications are supplied. It is advisable to re inspect the raw materials before putting them to actual use.
2. Fixing standards and specifications: In order to make any scheme of quality control successful, it is essential to predetermine standards and specifications. The practice should be to provide quality instructions in the form of drawings, showing shapes, dimensions and specifications describing color, strength, thickness, chemical composition, etc.
3. Exercising control over production operations: In order to execute efficient practices, the technical expert of the Quality Control Department must investigate, from time to time, the operating methods. Such investigation helps to eliminate all possible variables.
4. Locating inspection points: When the points at which defects occur are wrongly located or located with delay, it hinders quality control. Therefore there should first inspection of the raw materials at the vendor's places, then at the company's plant, then at the various points during the process of production and finally at the time of packing. The defects are likely to occur at these points. The finished goods can be cleared after obtaining 'O.K.' or 'All Correct' from the Quality Control Department.
5. Maintaining quality of equipments: The final quality of the products is conditioned by the quality of the equipments and other devices used. The Quality Control Department is responsible for testing the equipment used in inspection such as gauges, which measure dimensions, electronic devices, magnetic devices and industrial radio graphical instruments.
6. Maintaining records: The Quality Control Department is responsible for maintaining all records relating to quality inspection and control and the number rejected.
Advantages of Quality Control
Quality control is important as it offers certain advantages to the manufacturer. Such advantages are: stability to sale, goodwill in the market, ability to face market competition effectively, reduction in production costs, and elimination of wastage due to rejections and uniformity in production. These benefits are important for sales promotion and profit maximization. Manufacturers now give special attention to quality control techniques for long term benefits. Attention is given to research and development activities for this purpose. Even foreign collaborations are made for raising the quality standards of products manufactured. In brief, quality control is a matter of great importance in production management.
The benefits of quality control to consumes are: Availability of standard quality and reliable goods, proper reward for the price paid, safety to life and health, better standard of living and protection against substitution or adulteration and quick shopping of goods. Consumers always purchase standard quality goods even by paying a little higher price as they get full satisfaction over a long period from quality goods. Consumers, particularly educated consumers, support quality products as they know the benefits available from such standard quality products. This suggests the importance of quality control from the point of view of consumers.
The importance of quality control is, now, accepted even at the global level. Consumers now insist for superior quality goods. Expenditure on quality control is an investment for more sale and satisfaction to consumers. Quality control is a must for export promotion. Companies can capture foreign markets only by manufacturing superior quality goods at reasonable cost of production. Japan is a leading world exporter. This is mainly due to superior quality of goods manufactured in Japan. Governments in many countries support quality control measures. They provide all possible help for maintaining superior quality of goods. Restrictions are also imposed on the manufacturing of cheap goods. Even associations of manufacturers and traders support quality control measures. This suggests the importance of quality control in business.
In addition, the following advantages of quality control also suggest its importance:
1. Improvement in the quality of production and reduction in the production cost.
2. Uniformity in the production and supply of standard quality goods to consumers.
3. Offering full return of the price paid by consumers and giving convenience and satisfaction to consumers. This also develops cordial relations with consumers.
4. Reduction in spoiled production and rejection from consumers and dealers.
5. Promotion of exports due to superior and standard quality production.
6. Sales promotion in the internal market and facing market completion with confidence.
7. Reduction in the inspection cost.
8. Improvement in the productivity and motivation of employees.
9. Making the products popular in the market and thereby to develop market goodwill.
Source: Kalyan city Life Blog, Posted by: Gaurav Akrani, Dated 7/8/2010