Chapter 17: Net Present Value

15.1 Software Inspection Process

The benefits of using the Software Inspection Process to help produce 10,000 lines of code are $2,767,464. This was obtained by subtracting $1,742,533 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 inspections consist of the training and inspection costs. The training costs to prepare four people to use inspections to help produce 10,000 lines of code are $11,240. The inspection cost for our four trained inspectors to evaluate 10,000 lines of code is $70,833. This amounts to nearly 42 Software Inspection Process runs. That totals $82,073 to introduce the Software Inspection Process as a SPI method.

The development cost of $508,000, testing cost of $195,000, and maintenance cost of $967,900 were not included. The development, testing, and maintenance costs either stayed the same or decreased. Had the development, testing, or maintenance costs increased, the differences or the increases would have been included. Table 14 illustrates the B/CR of the Software Inspection Process.

Table 14: B/CR of Software Inspection Process

SPI Method	Benefits/Costs
Inspection Benefits	$2,767,464
Inspection Costs	$82,073
B/CR	34:1

Now we are ready to determine the B/CR of the Software Inspection Process to help produce 10,000 lines of code. Divide the benefits of $2,767,464 by the costs of $82,073 for the Software Inspection Process. The B/CR of using the Software Inspection Process to help produce 10,000 lines of code is 34:1.