21.5 Expert System Workflow Tools | ROI of Software Process Improvement: Metrics for Project Managers and Software Engineers

19.3 Analysis of Benefit/Cost Ratio

The B/CR of the Software Inspection Process to help produce 10,000 lines of code is 34:1. This is obtained by dividing the benefits of $2,767,464 by the costs of $82,073 for the Software Inspection Process.

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

The B/CR of using the Team Software Process ^SM to help produce 10,000 lines of code is 29:1. This is obtained by dividing the benefits of $4,341,496 by the costs of $148,400 for the Team Software Process ^SM .

The B/CR of using the Software Capability Maturity Model to help produce 10,000 lines of code is 10:1. This is obtained by dividing the benefits of $3,023,064 by the costs of $311,433 for the Software Capability Maturity Model .

The B/CR of using ISO 9001 to help produce 10,000 lines of code is 3:1. This is obtained by dividing the benefits of $569,841 by the costs of $173,000 for ISO 9001.

The B/CR of using Capability Maturity Model Integration to help produce 10,000 lines of code is 3:1. This is obtained by dividing the benefits of $3,023,064 by the costs of $1,108,233 for Capability Maturity Model Integration . Table 40 illustrates the analysis of B/CR.

Table 40: Analysis of Benefit/Cost Ratio
SPI Method	B/CR	Normalized
Inspection	34:1	0.80
Personal Software Process ^SM	42:1	1.00
Team Software Process ^SM	29:1	0.69
Software Capability Maturity Model	10:1	0.23
ISO 9001	3:1	0.08
Capability Maturity Model Integration	3:1	0.06

The SPI method with the highest B/CR is the Personal Software Process ^SM at 42:1. The SPI methods with the lowest B/CR are Capability Maturity Model Integration and ISO 9001 at 3:1. All of the SPI methods had a B/CR above 1:1. The Personal Software Process ^SM , Software Inspection Process, and Team Software Process ^SM have a B/CR of 42:1, 34:1, and 29:1, respectively.

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

A low B/CR may indicate high costs or low benefits or a combination of the two. A high B/CR may indicate low costs and high benefits or very high benefits and high costs.