Input Data Collection A very important aspect of software estimating is data collection. Data must be collected for inputs to the parametric tool and tool verification, validation, customization, and calibration.
Estimates generated by the tools are only as good as the input data used.
Careful analysis of all tool inputs are essential since small changes in input values can result in large variations in overall cost and schedules. Inputs vary between tools. Before using a tool, review input requirements and information collected, documentation, and examples provided with the tool. When possible, discuss these with individuals familiar with the tool. Using historical data as a basis for customizing or calibrating a tool is essential.