Reliability growth models for quality management

Software Quality ManagementU IVUnit – IV

Roy Antony Arnold Gy yAsst. Prof. / CSE

• Alth h li bilit th d l t• Although reliability growth models are meantfor reliability assessment, they are alsouseful for quality management at theuseful for quality management at theback end of the development process.

• Models developed from a previous product or Models developed from a previous product or a previous release of the same product can be used to track the testing defects of the

dcurrent product.• To have significant improvement, the defect

i l t ( f il d i ) f h arrival rate (or failure density) of the current project must fall below the model curvecurve.

• The QIP involved five extra activities:• The QIP involved five extra activities:1. Blitz testing — "artistic" testing in stressfulenvironments.

2. Customer evaluation — customers conductingtesting in the development laboratory.

3 Code inspections additional inspections of3. Code inspections — additional inspections oferror-prone modules, especially routines that aredifficult to test such as the error

/ ti h dli tirecovery/exception handling routines.4. Design reviews — re-review of designs of suspectcomponents and modules.p

5. Extension of system test — improvement of testsuites and extension of testing schedules to allowthorough final test execution.thorough final test execution.

• Because of the special QIP activities, theproduct ship date was delayed onep p ymonth.

• As a result more than 250 field defects• As a result, more than 250 field defectswere found and removed.

• The field quality of the product, evidencedby field defect arrivals reported in latery pyears, improved significantly.