9.4 TSPSM ROI Methodology

8.6 PSP ^SM Breakeven Point Methodology

The breakeven point methodology for the Personal Software Process ^SM is a procedure to determine when benefits exceed costs. The benefits for the Personal Software Process ^SM rapidly exceed its cost due to reduced maintenance costs. Breakeven point is the value at which the benefits overtake the costs for using the Personal Software Process ^SM . Its breakeven point methodology is a four-part process that consists of estimating productivity and the cost to productivity difference ratio. Its breakeven point methodology consists of combining costs with productivity difference using the breakeven point formula. Key elements include determining the ratio of productivity for the old and new software process improvement methods . These are used to determine the point when the benefits overtake the costs. Figure 38 illustrates the breakeven point methodology for the Personal Software Process ^SM .

Figure 38: Breakeven Point Methodology for Personal Software Process ^SM

Estimate testing productivity for PSP ^SM : The objective of this activity is to determine the software productivity associated with using the software testing process. This substep includes: divide software size by total life cycle cost of testing for PSP ^SM .

Estimate PSP ^SM productivity for PSP ^SM : The objective of this activity is to determine the software productivity associated with using PSP ^SM . This substep includes: divide software size by total life cycle cost of PSP ^SM for PSP ^SM .

Estimate productivity difference for PSP ^SM : The objective of this activity is to compare the productivity of software testing to that of PSP ^SM . This substep includes: divide test productivity by PSP ^SM productivity for PSP ^SM .

Estimate cost to productivity difference ratio for PSP ^SM : The objective of this activity is to determine when PSP ^SM will begin paying for itself. This substep includes: divide special cost by one less productivity difference for PSP ^SM .