An industrial survey of requirements interdependencies in software product release planning

The task of finding an optimal selection of requirements for the next release of a software system is difficult as requirements may depend on each other in complex ways. This paper presents the results from an in-depth study of the interdependencies within 5 distinct sets of requirements, each including 20 high-priority requirements of 5 distinct products from 5 different companies. The results show that (1) roughly 20% of the requirements are responsible for 75% of the interdependencies, (2) only a few requirements are singular, (3) customer-specific bespoke development tend to include more functionality related dependencies whereas market-driven product development have an emphasis on value-related dependencies. Several strategies for reducing the effort needed for identifying and managing interdependecies are outlined. A technique for visualization of interdependecies with the aim of supporting release planning is also discussed. The complexity of requirements interdependency analysis is studied in relation to metrics of requirements coupling. Finally, a number of issues for further research are identified.