Quality characteristics

Any feature or characteristic of a product or service which is needed to satisfy customer needs or achieve fitness for use is a quality characteristic. When dealing with products the characteristics are almost always technical characteristics, whereas service quality characteristics have a human dimension. Some typical quality characteristics are given in the table below. 

These are the characteristics which need to be specified and their achievement controlled, assured, improved, managed, and demonstrated. These are the characteristics which form the subject matter of the specified requirements referred to in ISO 9000. When the value of these characteristics is quantified or qualified they are termed quality requirements or requirements for quality. ISO 8402 1994 defines requirements for quality as an expression of the needs or their translation into a set of quantitatively or qualitatively stated requirements for the characteristics of an entity to enable its realization and examination. While rather verbose, this definition removes the confusion over quality requirements and technical requirements. (An additional definition is provided in Appendix A.) Technical requirements for a product or service are quality requirements. The requirements of ISO 9000 are quality system requirements. 

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The chart consists of a central line and two pairs of limit lines or simply of a central line and one pair of control limits. By plotting a sequence of points in order, a continuous record of the quality characteristic is made available. Trends in data or sudden lack of precision can be made evident so that the causes may be sought. 

W. Harm and P. A. Jensen, Water Quality Characteristics of Ha rdous Materials, Texas A M University, College Station, 1974, p. 4. 

Some companies that let toll contracts have been known to work with small tollers who displayed excellent technical, safety, and quality characteristics to help them achieve the necessary higher production capacity. This is feasible if the time frame allows and a closer relationship is mutually beneficial. 

In making his (her) recommendations, the pharmacist must realize that two types of instant teas are available, which, as a result of the manufacturing process and the resulting quality characteristics, are very different from each other ... 

What water quality characteristic would reduce the efficiency of UV in destroying pathogens contained in water ... 

Ensuring that the policy is relevant to the expectations and needs of the organization s customers is a little more difficult. Companies need to predict what their customer expectations and needs are (now a requirement in clause 4.1.4 under Business plans). They may be beyond what they specify in contracts although they may in fact be identical to such specifications. For companies to create satisfied customers they not only need to meet requirements specified by the customer but meet national and international legislation and have consideration for the needs and expectations of society. As explained in Part 1 Chapter 1 on Quality characteristics, customers are not only the buyers but comprise several other interested parties. You need to provide a means of determining what the customer expectations and needs are and then subject the written quality policy to a review against those expectations and needs to determine if there is any conflict. As part of your business planning procedure you should indicate how you determine your customer s current and future needs and expectations. 

To determine trends in customer satisfaction and dissatisfaction you will need to make regular surveys and plot the results, preferably by particular attributes or variables. The factors will need to include quality characteristics of the product or service as well as delivery performance and price. The surveys could be linked to your improvement programs so that following a change, and allowing sufficient time for the effect to be observed by the customer, customer feedback data could be secured to indicate the effect of the improvement. 

Productivity is a measure of productive efficiency calculated as the ratio of what is produced to what is required to produce it. Productivity can therefore be considered as a characteristic of a process, and therefore a measure of the quality of a process. Consider two process each producing the same product but one delivers the result using less resources and hence as a consequence has a higher productivity. The process with the higher productivity could thus be regarded as being of better quality. However, measuring resource consumption alone would not be a valid means of comparison as inputs could be vastly different. Hence productivity is a quality characteristic. 

You should review the contract and the detail specifications to identify whether your existing controls will regulate quality within the limits required. You may need to change the limits, the standards, the techniques, the methods, the environment, and the instruments used to measure quality characteristics. One technique may be to introduce Just-in-time as a means of overcoming storage problems and eliminating receipt inspection. Another technique may be Statistical Process Control as a means of increasing the process yield. The introduction of these techniques needs to be planned and carefully implemented. 

Should you need any new instrumentation, either for monitoring processes or for measuring quality characteristics, you need to make provision for its development. You will need to develop detail specifications of the instrumentation, and design, manufacture, inspect, and install the instruments under controlled conditions which meet the requirements of the standard. 

Design input requirements may in fact be detailed in the contract. The customer may have drawn up a specification detailing the features and characteristics product or service needs to exhibit. (See Part 1 Chapter 1 on Quality characteristics and Part 2 Chapter 3 under Ensuring that the requirements are adequately defined and documented.) Alternatively, the customer needs may be stated in very basic terms for example ... 

Quality characteristics Quality conformance Quality control... 

A technique to deploy customer requirements (the true quality characteristics) into design characteristics (the substitute characteristics) and deploy them into subsystems, components, materials, and production processes. The result is a grid or matrix that shows how and where customer requirements are met. 

An even simpler and perhaps more effective approach to the problem might be application of the resazurin test as applied in the milk industry for indirect estimation of bacterial population. Proctor and Greenlie (34) have suggested this application, and Wolford (38) has worked with it in a limited way. The test is based upon a color change involved in the reduction of the dye. The time required for reduction decreases with increase in bacterial numbers. Intensive investigation of this method and its application with respect to increasing its sensitivity, and correlation of reaction rates with bacterial population and quality characteristics of the product, might be of considerable value. 

A great deal of effort has been made to investigate the role of xylans in bread making. Reviews on cereal xylans [39,41,118] have shown that the xylan component is primarily responsible for the effects on the mechanical properties of the dough as well as the texture and other end-product quality characteristics of baked products. 

Composition of discrete (difference) approximations to equations of mathematical physics and verifying a priori quality characteristics of these approximations, mainly the error of approximation, stability, convergence, and accuracy of the difference schemes obtained ... 

Given a set of existing (x, y) data records, where x is a vector of operating or decision variables, which are believed to influence the values taken on by y, y is a performance metric, usually assumed to be a quality characteristic of the product or process under analysis ... 

Quality characteristics of tomato juice from wild-type and transgenic Rutgers... 

A complete list of components designated by names or codes sufficiently specific to indicate any special quality characteristic ... 

Mineral resources are broadly divided into discovered and the undiscovered categories. Features such as size, quality, characteristics and exact location of individual resources are matters of almost pure speculation for the latter. Undiscovered resources are unlikely to contribute much to the total supply in the immediate future. In the case of discovered resources estimates can be made, with an indication of the degree of reliability, of the timing and the future rates of production on a deposit-by-deposit basis. Using such estimation the occurrence and the likely rate of future availability can be combined in plots such as those shown in Figure 1.18 for discovered resources. Three situations are depicted. The first corresponds to future supply from sources that are reliable, the second to likely sources... 

The purpose of in-use stability studies is to establish the period for which a product intended to be used on more than one occasion may be used after reconstitution or dilution or the withdrawal of the first dose from the container without adversely affecting the integrity of the product and with the product retaining acceptable quality characteristics. This type of test can be applied to any multiple use product (e.g., sterile products in multiple-use containers, powders or granules including those used to produce oral solutions or suspensions) but is likely to be of particular importance in the case of products that are manufactured with an inert headspace gas, for products containing antioxidants to protect an active ingredient that is liable to oxidative decomposition, and for products that contain a volatile antimicrobial preservative. 

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