18.3 Team Software ProcessSM

16.2 Personal Software Process ^SM

The benefits of using the Personal Software Process ^SM to help produce 10,000 lines of code are $4,469,997. This was obtained by subtracting $40,000 in new total life cycle costs from $4,509,997 in old total life cycle costs.

The special, new, or additional costs that are required to introduce the Personal Software Process ^SM consist of only the training cost. The training cost to use the Personal Software Process ^SM to help produce 10,000 lines of code is $105,600.

The development cost of $40,000 was not included as a Personal Software Process ^SM cost. The development cost actually decreased. Had the development cost of the Personal Software Process ^SM increased, the difference or increase would have been included.

Let's determine the B/CR of the Personal Software Process ^SM to help produce 10,000 lines of code. Divide the benefits of $4,469,997 by the costs of $105,600 for the Personal Software Process ^SM . The B/CR of using the Personal Software Process ^SM to help produce 10,000 lines of code is 42:1.

However, the benefits of the Personal Software Process ^SM must be adjusted, by first removing the costs. That is, the costs of inserting the Personal Software Process ^SM as a SPI method must first be removed from the gross benefits. We will call these the adjusted benefits of the Personal Software Process ^SM . Subtract $105,600 in Personal Software Process ^SM costs from $4,469,997 in gross Personal Software Process ^SM benefits. The result is $4,364,397 in adjusted benefits. Table 21 illustrates the ROI of the Personal Software Process ^SM .

Table 21: ROI of Personal Software Process ^{S M}

SPI Method	Benefits/Costs
PSP SM Benefits (Gross)	$4,469,997
PSP SM Costs	$105,600
PSP SM B/CR	42:1
PSP SM Benefits (Adjusted)	$4,364,397
ROI	4,133%

Now we are ready to determine the ROI of the Personal Software Process ^SM to help produce 10,000 lines of code. Divide the adjusted benefits of $4,364,397 by the costs of $105,600 for the Personal Software Process ^SM . Multiply the result by 100%. The ROI of using the Personal Software Process ^SM to help produce 10,000 lines of code is 4,133%.