Phase distribution of software development effort

Effort distribution by phase or activity is an important but often overlooked aspect compared to other steps in the cost estimation process. Poor effort allocation is among the major root causes of rework due to insufficiently resourced early activities. This paper provides results of an empirical study on phase effort distribution data of 75 industry projects, from the China Software Benchmarking Standard Group (CSBSG) database. The phase effort distribution patterns and variation sources are presented, and analysis results show some consistency in effects of software size and team size on code and test phase distribution variations, and some considerable deviations in requirements, design, and transition phases, compared with recommendations in the COCOMO model. Finally, this paper discusses the major findings and threats to validity and presents general guidelines in directing effort allocation. Empirical findings from this study are beneficial for stimulating discussions and debates to improve cost estimation and benchmarking practices.