KC-1.2.1-The Different Views of Quality

The Two Quality Gaps

The definitions in summary are given below. For those who love to read more, further info is given.

From the customer's perspective, satisfaction after the delivering of the product is the ultimate validation of the product quality. It is clear that the concept of quality must involve customers or, simply put, quallity is conformance to customers' expectations and requirements. Crosby's "conformance to requirements" and Juran's "fitness for use" both implied the customers' perspective.

From the producer's perspective, developing and producing the product in accordance with the specifications is the path to achieving quality.

Therefore the three ideal metrics any organization should have are product quality, process quality, and customer satisfaction (referred to as the big capital "Q").

From a high-level definition of a concept, to a product being operationally defined, many steps are involved, each of which may be exposed to possible shortcomings. For example, to achieve the state of conformance to requirements, customers' requirements must first be gathered and analyzed, then specifications from those requirements must be developed, and the product must be developed and manufactured appropriately. In each phase of the process, errors may have occurred that will negatively affect the quality of the finished product. The requirements may be erroneous (especially in the case of software development), the development and manufacturing process may be subject to variable that induce defects, and so forth. Form the customer's perspective, satisfaction after the purchase of the product is the ultimate validation that the product conforms to requirements and is fit to use. From the producer's perspective, once requirements are specified, developing and producing the product in accordance with the specifications is the basic step to achieving quality. Usually, for product quality, lack of functional defeats and good reliability are the most basic measures. In order to be "fit for use," the product first has to be reliably functional.

Because of the two perspectives on quality (i.e., customer satisfaction as the ultimate validation of quality, alnd the producer's adherence to requirements to achieve quality), the de facto definition of quality consists of two levels. The first is the intrinsic product quality, often operationally limited to product quality,often operationally limited to product defect rate and reliability; this narrow definition is referred to as the "small" q (q for quality). The broader level of the definition of quality includes both product quality and customer satisfaction; it is referred to as the "big" Q.

In software, the norrowest sense of product quality is comonly recongnized as lack of "bugs" in the product. This definition is usually expressed in two ways: defect rate (e.g., number of defects per million lines of source code, or per function point), and reliability (e.g., number of failure per n hours of operation, mean time to failure, or the probability of failure-free operation in a specified time). Customer satisfaction is usually measured by the percentage of those satisfied or nonsatisfied (neutral and dissatisfied) on customer satisfaction surveys. To reduce bias, usually techniques such as double-blind surveys (the interviewer not knowing who the customer is, and the customer not knowing what company the interviewer represents) are used. In addition to overall customer satisfaction with the software product, satisfaction toward specific attributes is CUPRIMDSO satisfaction levels of its software products (i.e., capability [functionality], usability, performance, reliability, instalability, maintainability, documentation/information, service, and overall satisfaction). The Hewlett-Packard Co. focuses on FURPS (functionalilty, usability, relability, performance, and supportability)[1].

For people with much more interest, here is the link from HP's Center for Quality Management Journal. I believe the differences between Customer's & Producer's view of qualities cant be better enumerated. The copyrights do not allow to reproduce any part of it. You can go to this link to find this quite a long paper: http://cqmextra.cqm.org/cqmjournal.nsf/reprints/rp08300
The PDF form of this article can be downloaded from this link: DOWNLOAD Article(PDF)

References:

1. Software quality: an overview from the perspective of total quality management - Tutorial - IBM Systems Journal, March, 1994 by Stephen H. Kan, Victor R. Basili , L arry N. Shapiro