8. At this time, only the number of complex,
nominal, and simple requirement elements have been estimated; therefore, line 5
through line 10 show the remaining estimated number of elements as TBD (to be
determined). Later in the project??™s life cycle, as estimates for these other elements
become available, they would be added to the model.
Historical Effort Distribution (Line 12)
This shows that, historically, projects have taken 20 percent of total staff effort in
the Requirements phase, 30 percent in the Design phase, 20 percent in the Implementation
phase, 15 percent in the Integration phase, and 15 percent in the Systems
Test phase. (We have simplified the effort distribution percentages to make the
example easier to follow.)
Estimates
The model has two estimates:
1. The first estimate on line 15 is based on the estimated number of PPB elements
that most affect each phase. You can see how this is computed by
looking at the value under the requirement phase. This value is computed by
multiplying the estimated number of requirements by the mean number of
effort hours for that type of requirement:
Number of complex reqs ?— mean effort req phase for complex reqs = 75
?— 35 = 2,625
??’
A High-Maturity Perspective n 263
Number of nominal reqs ?— mean effort req phase for nominal reqs = 100
?— 21 = 2,100
Number of simple reqs ?— mean effort req phase for simple reqs = 200
?— 8.
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