Numerous textbooks address software testing in a structured development environment. By “structured” is meant a well-defined development cycle in which discretely defined steps provide measurable outputs at each step. It is assumed that software testing activities are based on clearly defined requirements and software development standards, and that those standards are used to develop and implement a plan for testing. Unfortunately, this is often not the case. Typically, testing is performed against changing, or even wrong, requirements.

This text aims to provide a quality framework for the software testing process in traditional structured as well as unstructured environments. The goal is to provide a continuous quality improvement approach to promote effective testing methods and provide tips, techniques, and alternatives from which the user can choose.

The basis of the continuous quality framework stems from Edward Deming’s quality principles. Deming was the pioneer in quality improvement, which helped turn Japanese manufacturing around. Deming’s principles are applied to software testing in the traditional “waterfall” and rapid application “spiral (or agile)” development (RAD) environments. The waterfall approach is one in which predefined sequential steps are followed with clearly defined requirements. In the spiral approach, these rigid sequential steps may, to varying degrees, be lacking or different.