A REENTRANT LINE MODEL FOR SOFTWARE PRODUCT TESTING

In today's competitive environment for software products, quality is a n important characteristic. The development of large-scale software pr oducts is a complex and expensive process. Testing plays a very import ant role in ensuring product quality. Improving the software developme nt process leads to improved product quality. We propose a queueing mo del based on re-entrant lines to depict the process of software module s undergoing testing/debugging, inspections and code reviews, verifica tion and validation, and quality assurance tests before being accepted for use. Using the re-entrant line model for software testing, bounds on test times are obtained by considering the state transitions for a general class of modules and solving a linear programming model. Sche duling of software modules for tests at each process step yields the c onstraints for the linear program. The methodology presented is applie d to the development of a software system and bounds on test times are obtained. These bounds are used to allocate time for the testing phas e of the project and to estimate the release times of software.