21.6 Self-Documenting Approaches | ROI of Software Process Improvement: Metrics for Project Managers and Software Engineers

19.4 Analysis of Return on Investment

The ROI of using the Software Inspection Process to help produce 10,000 lines of code is 3,272%. This is obtained by dividing the adjusted benefits of $2,685,391 by the costs of $82,073 and multiplying the result by 100%.

The ROI of using the Personal Software Process ^SM to help produce 10,000 lines of code is 4,133%. This is obtained by dividing the adjusted benefits of $4,364,397 by the costs of $105,600 and multiplying the result by 100%.

The ROI of using the Team Software Process ^SM to help produce 10,000 lines of code is 2,826%. This is obtained by dividing the adjusted benefits of $4,193,096 by the costs of $148,400 and multiplying the result by 100%.

The ROI of using the Software Capability Maturity Model to help produce 10,000 lines of code is 871%. This is obtained by dividing the adjusted benefits of $2,711,631 by the costs of $311,433 and multiplying the result by 100%.

The ROI of using ISO 9001 to produce 10,000 lines of code is 229%. This is obtained by dividing the adjusted benefits of $396,841 by the costs of $173,000 and multiplying the result by 100%.

The ROI of using Capability Maturity Model Integration to help produce 10,000 lines of code is 173%. This is obtained by dividing the adjusted benefits of $1,914,831 by the costs of $1,108,233 and multiplying the result by 100%. (This assumes that the benefits are no greater than the Software Capability Maturity Model .) Table 41 illustrates the analysis of ROI.

Table 41: Analysis of Return on Investment
SPI Method	ROI	Normalized
Inspection	3,272%	0.79
Personal Software Process ^SM	4,133%	1.00
Team Software Process ^SM	2,826%	0.68
Software Capability Maturity Model	871%	0.21
ISO 9001	229%	0.06
Capability Maturity Model Integration	173%	0.04

The SPI method with the highest ROI is the Personal Software Process ^SM at 4,133%. The SPI method with the lowest ROI is Capability Maturity Model Integration at 173%. All of the SPI methods had an ROI above 100%, topping out with the Personal Software Process ^SM , Software Inspection Process, and Team Software Process ^SM at 4,133, 3,272, and 2,826%, respectively.

On a normalized scale, the Personal Software Process ^SM has the highest ROI. ISO 9001 and Capability Maturity Model Integration have the lowest ROI on a normalized scale.