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.
| 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.