Database validation is an important step in ensuring that you have quality data in your historical database. I've talked before about the importance of collecting project data and what you can do with your own data, but it all hinges on having thoroughly vetted project history.
Although it's nice to have every tab in SLIM-DataManager filled out, we really only need three key pieces of information to calculate PI:
- Size (Function Unit): if the function unit is not SLOC, a gearing factor should be provided (97.3% of projects in the database report total size)
- Phase 3 duration or start and end dates (99.9% of projects in the database report phase 3 duration)
- Phase 3 effort (99.9% of projects in the database report phase 3 effort)
These fields can be thought of as the desired minimum information needed, but even if one is missing, you may not want to delete the project from the database. A project that is missing effort data, for instance, will not have a PI but could be used to query a subset of projects for average duration by size. Likewise, a project with no size will not have a PI, but does contain effort and duration information that could be useful for calculating the average time to market for a division. However, if possible, it is a good idea to fill out at least these three fields.