Preface.

This article introduces a series of articles on software testing and development. Hailpern and Santhanam provide formal definitions for debugging, testing and verification and show how each activity relates to the software development process. Bassin, Biyani and Santhanam describe metrics that can be applied as part of the acceptance test for vendor-developed software. The authors explain how metrics can be used to estimate the degree of risk involved in accepting a software component, based on test case execution. The paper by Butcher, Munro and Kratschmer describes case studies in which Orthogonal Defect Classification, a quantitative method used to improve processes as products evolve, was applied to a mature product, a large middleware product, and small team project. Weyuker and Avritzer introduce the performance nonscalability likelihood metric, designed to predict the likelihood that the system will fail to meet its performance goals when the workload is scaled. Loveland and colleagues report on the process, tools and techniques used to test z/OS, the operating system for the IBM zSeries processors. Edelstein and colleagues describe ConTest, a tool that both generates and executes tests for detecting synchronization problems in multithreaded Java programs.