Concept Number: *060
English Master: Remaining Major Defects
Synonyms, Variations & Acronyms: none
1. The estimate is based on:
See Section 8.6 for a worked example.
2. The Defect density is usually expressed as the number of remaining Major-Defects/(logical) page.
3. It is important to understand that we do not know precisely where such Defects are located, and we do not know exactly what they are. This is an estimate of the current total of the Defect Quantity remaining, Before or After editing or Debugging.
4. The estimate seems to be accurate to about plus or minus 30%. In rougher terms, experience shows that for every Defect, which SQC finds and fixes, there is about one more left, which will be discovered by future QC (test, or another SQC) or customer use.
5. The “remaining Defects” estimate is primarily used to make an Exit decision from a test or QC Process. The “remaining Defects estimate” represents calculable future costs. One Major-Defect cured saves about 10 hours downstream with about 25%-35% probability. These downstream costs can be weighed against the Cost of removing Defects immediately, Before proceeding further.
This Concept entered by Diane O'Brien.