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CHAPTER 5 SOFTWARE PROJECT PLANNING 129

FIGURE 5.3
Function Estimated LOC
Estimation
table for the
LOC method User interface and control facilities (UICF) 2,300
Two-dimensional geometric analysis (2DGA) 5,300
Three-dimensional geometric analysis (3DGA) 6,800
Database management (DBM) 3,350
Computer graphics display facilities (CGDF) 4,950
Peripheral control function (PCF) 2,100
Design analysis modules (DAM) 8,400

Estimated lines of code 33,200

Applying Equation (5-1), the expected value for the 3D geometric analysis function is 6800
LOC. Other estimates are derived in a similar fashion. By summing vertically in the esti-
Do not succumb to the mated LOC column, an estimate of 33,200 lines of code is established for the CAD system.
temptation to use this A review of historical data indicates that the organizational average productivity
result as your for systems of this type is 620 LOC/pm. Based on a burdened labor rate of $8000 per
estimate. You should month, the cost per line of code is approximately $13. Based on the LOC estimate
derive another
estimate using a and the historical productivity data, the total estimated project cost is $431,000 and
different method. the estimated effort is 54 person-months. 12

5.6.4 An Example of FP-Based Estimation
Decomposition for FP-based estimation focuses on information domain values rather
than software functions. Referring to the function point calculation table presented in
Figure 5.4, the project planner estimates inputs, outputs, inquiries, files, and external
WebRef interfaces for the CAD software. For the purposes of this estimate, the complexity weight-
Information on FP cost ing factor is assumed to be average. Figure 5.4 presents the results of this estimate.
estimating tools can be
obtained at Est. FP
www.spr.com Information domain value Opt. Likely Pess. count Weight count

Number of inputs 20 24 30 24 4 97
Number of outputs 12 15 22 16 5 78
Number of inquiries 16 22 28 22 5 88
FIGURE 5.4 Number of files 4 4 5 4 10 42
Estimating Number of external interfaces 2 2 3 2 7 15
information
domain Count total 320
values

12 Estimates are rounded-off to the nearest $1,000 and person-month. Arithmetic precision to the
nearest dollar or tenth of a month is unrealistic.