SOFTWARE PROCESS DEVELOPMENT

As an organization becomes more comfortable with the collection and use of
process metrics, the derivation of simple indicators gives way to a more rigorous
approach called statistical software process improvement (SSPI). In essence, SSPI uses
software failure analysis to collect information about all errors and defects3 encountered
as an application, system, or product is developed and used. Failure analysis
works in the following manner:
1. All errors and defects are categorized by origin (e.g., flaw in specification,
flaw in logic, nonconformance to standards).
2. The cost to correct each error and defect is recorded.

3. The number of errors and defects in each category is counted and ranked in
descending order.
4. The overall cost of errors and defects in each category is computed.
5. Resultant data are analyzed to uncover the categories that result in highest
cost to the organization.
6. Plans are developed to modify the process with the intent of eliminating (or
reducing the frequency of) the class of errors and defects that is most costly.