A study to investigate the impact of requirements instability on software defects

Abstract

Software development is a dynamic process and is characterized by change. Software projects often begin with unclear, ambiguous, and incomplete requirements which give rise to intrinsic volatility. Constant change in requirements is one of the main causes of software defects and a major issue faced by the software industry. This paper describes the findings of our research-based study that investigates the impact of both the pre-release and post-release requirements changes on overall defects by defining measures, collecting data against those measures and analyzing the collected data through statistical techniques. Our findings, based on industry data from 4 software projects consisting of 30 releases, all in e-commerce domain, indicate that there is a significant relationship between pre/post release change requests initiated by the client and software defects. In addition, our data analysis indicates that changes in the design of the system at the later stages of software development i.e., during coding, testing and after release have a significant impact on the high severity defects that affect the major functionality of the system. Also, we found that insufficient time spent on the design phase and inadequate communication with the client could be some of the causes of requirements changes and consequently software defects.