Establish Technical Baseline, Ground Rules, and Assumptions
To establish an accurate technical baseline, you must first define the functionality that must be estimated. Recognize the constraints associated with the application and the project, and determine what functionality must be developed versus what can be provided via COTS or reuse.
Ground rules are concise statements that describe the basis from which the estimate is made. “This estimate includes functions a, b, and c only; no costs associated with travel are included” is an example of a ground rule.
Assumptions are suppositions that describe unknown variables that will affect an estimate. “This estimate assumes the software developer will use development system X” is an example of an assumption. Later in the project when you confirm that “development system X” will be employed, this proven assumption would then be restated as a ground rule.
Ground rules and assumptions form the foundation of the estimate and, although in the early stages of the estimate they are preliminary and therefore rife with uncertainty, they must be credible and documented. Review and redefine these assumptions regularly as the estimate moves forward.
Step One: Establish estimate scope
Step Three: Collect Data