AUTOMATED ESTIMATION TOOLS

The decomposition techniques and empirical estimation models described in the preceding
sections are available as part of a wide variety of software tools. These automated
estimation tools allow the planner to estimate cost and effort and to perform
"what-if" analyses for important project variables such as delivery date or staffing.
Although many automated estimation tools exist, all exhibit the same general characteristics
and all perform the following six generic functions [JON96]:
1. Sizing of project deliverables. The “size” of one or more software work
products is estimated. Work products include the external representation of
software (e.g., screen, reports), the software itself (e.g., KLOC), functionality
delivered (e.g., function points), descriptive information (e.g. documents).
2. Selecting project activities. The appropriate process framework  is selected and the software engineering task set is specified.
3. Predicting staffing levels. The number of people who will be available to
do the work is specified. Because the relationship between people available
and work (predicted effort) is highly nonlinear, this is an important input.
4. Predicting software effort. Estimation tools use one or more models (e.g.,
Section 5.7) that relate the size of the project deliverables to the effort
required to produce them.
5. Predicting software cost. Given the results of step 4, costs can be computed
by allocating labor rates to the project activities noted in step 2.
6. Predicting software schedules. When effort, staffing level, and project
activities are known, a draft schedule can be produced by allocating labor
across software engineering activities based on recommended models for
effort distribution.