32.1.1 The Meaning of Software Quality

Defining quality, in general, is a difficult task. Different people and organizations define quality in a number of different ways. Most people associate quality with a product or service in order to satisfy the customer s requirements. According to Uselac [1], Quality is not only products and services but also includes processes, environment, and people . Also, Deming [2], in his famous work says that quality has many different criteria and that these criteria change continually . This is the main reason to measure consumer preferences and to remeasure them frequently , as Goetsch and Davis [3] observe. Finally, they conclude: Quality is a dynamic state associated with products, services, people, processes and environments that meets or exceeds expectations .

What about software? Software is the component that allows a computer or digital device to perform specific operations and process data. Mainly, software consists of computer programs. However, databases, files, and operating procedures are closely related to software. Any user deals with two categories of software: the operating system controlling the basic operations of the digital system and the application software controlling the data processing for specific computer applications like computer-aided drafting, designing and manufacturing, text processing, and so on.

Like any other product, quality software is that which does what the customer expects it to do. The purpose for which a software system is intended is described in a document usually known as the user requirements specification. User requirements fall into two...