What is Quality?

Nov.05, 2009 in 6 Sigma, FMEA

Quality and quality control have attracted the attention of many industrialists during the last few decades. The success of many manufacturing and servicing industries has been linked directly or indirectly to the quality of the products and services provided. A widely quoted example is the development of Japanese products during the last 20 to 30 years. It was, at one time, being branded as a nation that produced cheap and shoddy products but that image has rapidly been changed to its present highly acclaimed status of an industrialised nation noted for its high quality products. The success story lies in the manufacture of quality products and, more importantly, through strict quality control the products are manufactured
at far less cost than its competitors.

But what is quality? And, what is quality control ?

What is Quality?

Different people may have different views on what quality is. To many, quality typically connotes the meaning of pleasant visual appearance, dimensional accuracy, good performance including long service life, good surface finish and reliability.

The Japanese Industrial Standards defined quality as:

A characteristic property to be the object of valuation for determining whether or not an article or service is satisfying its purpose.

Based on the above definition, quality can be summarised as: Satisfaction of customers’ needs
Suitability for intended use Performance according to specification

As different categories of consumers may have different levels of satisfaction, quality in this instance could be translated to the different grade or standard of products that a manufacturer can produce. For instance, if you are talking about automobiles, it denotes the difference between a luxury car and a popular automobile. The customer group that the product was targeted at is different from the very beginning.

The different levels of satisfaction will mean different costs to meet the specifications. Therefore, manufacturers should be concerned with the consistency in meeting these specifications. Quality in this sense means conformity to a prescribed standard or specification. In this instance, quality has to do with the difference in how well a product is made and targeted for the same purpose. Poor quality simply means a deviation from the prescribed standard or specification. As efforts to conform incur costs, a compromise should be made to achieve an optimum level of conformance.
Summarising from the above, quality is defined by the customers’ needs. Manufacturers must be able to translate the customers’ needs into a set of precise specifications and manufacture according to the prescribed standard. In addition, it is normal to expect that customers’ expectations are not always static. With technological developments, competitions and new designs, customers constantly expect improvements in quality. This means the manufacturers will have to constantly upgrade their quality levels.
DEFINITIONS OF QUALITY

-Quality Products are those that: Satisfy customers’ expectations
-Meet a well defined need, use or purpose
-Comply with applicable standards and specifications
-Comply with statutory and other requirements of society
-Are available at competitive prices
-Are provided at a cost which will yield profit

Need for Quality Control

As a general rule, if defects are eliminated or minimised through quality control, the cost of production will decrease.
It is simply common sense that when products which deviate from the intended standard are made, they must either be repaired or discarded and this would obviously incur extra costs. If it is possible to turn out goods that will fullfil the standard, naturally costs will decrease in addition to improved customers’ satisfaction. It is therefore appropriate to clearly define first what quality control is before we identify the need for quality control.

The most common notion of quality control is the checking or inspection of the product to ensure its conformance to specifications.

The Japanese Industrial Standards defined quality control as:

Quality Control is a system comprising all the means used in the economically manufacturing of products or services that meet the quality requirements of the buyer.

Quality control should therefore encompass the activities of Prevention, Detection and Correction of product defects that could cause customers’ dissatisfaction. The key point in quality control is therefore the faithful conformance of the product specifications or standard. Product defects or deviations from specifications can result from any or combination of some of the following: Poor product design
Defective raw material Inadequate, inappropriate machines and tools Inappropriate environment
Human errors.

A Quality Control System or Quality Management should therefore be designed and instituted to cover all these areas. The basic elements in quality control which can be translated directly into the objectives of a Quality Control System or Quality Management are: To maintain design standards
-To meet customers’ specifications
-To determine department/personnel effectiveness
-To detect and correct defective products

The above objectives, besides the assurance of conformity to specifications and customers’ satisfaction, will also reduce production and increase productivity. Both these benefits are the results of reducing parts and components that continuously and consistently meet the specifications. The ultimate objective is to ensure that every piece of the product leaving a manufacturing plant is made correct from the very first step. This will mean no rejection, no re-work, no scrap; and hence, lower cost of production leading to an overall increase in productivity. It sounds simple and easy but the goal is far more difficult to achieve than one would expect. Detailed methodologies and procedures for Quality Control will need to be designed and formulated. These will be discussed in the subsequent posts.