. Documenting requirements using Volere
The project used Volere shells to document the requirements it identified (see Figure 8). The team developed a database to capture the evolving requirements, and to allow all project partners around the world to view and edit them. Using the Volere shell had a number of advantages (Sharp et al, 2003):
1. As all requirements were documented using this format we had consistent information for each requirement together with traceability information to track where the requirement originated, and where it appears in later documentation such as UML diagrams.
2. Having requirements documented in a consistent manner facilitated the identification of common requirements across scenario strands.
3. The format is clear and simple to follow.
4. The format encourages the originator of a requirement to study the detail of the requirement (description), to justify it (rationale) and to consider how it relates to other requirements (dependencies/conflicts).
5. Completing the 'Fit Criterion' field requires the originator to think about how the requirement can be tested or evaluated. This fed directly into our evaluation activities and supported the work there.
6. Volere shells were stored in a database for easy search and retrieval. As the number of requirements grew, the database was updated.