Requirements uncertainty: influencing factors and concrete improvements

Practically all industry studies on software project results conclude that good requirements engineering plays a pivotal role for successful projects. A key reason for project failures is insufficient management of changing requirements during all stages of the project life cycle. This article investigates one of the root causes for changing requirements, namely requirements uncertainty. In an experimental field study we looked into four underlying drivers for requirements uncertainty. We found several techniques must be used simultaneously to see tangible success. Using only one such technique in isolation doesn't make a difference. The field study is supported by extensive data from well over 200 projects stemming from very different business areas of Alcatel over a period of two years. Results are presented with practical experiences to allow effective transfer.