Inspection is a necessary but non-value-adding activity whose purpose is to protect the customer from poor quality. We should therefore do as little as possible, upon condition that our inspection plan meet the customer’s requirement. Inspection plans with acceptance numbers of zero (c=0) minimize the sample size, albeit at the cost of a higher producer’s risk of rejecting lots at the specified acceptable quality level (AQL). This presentation will show how to define c=0 plans whose customer protection is equivalent to that of the corresponding ANSI/ASQ Z1.4 (formerly MIL-STD 105) plan.
Areas Covered in the Session :
- How to use ANSI/ASQ Z1.4, including definition of the sampling plan based on the inspection level, acceptable quality level (AQL), and lot size.
- How to use the standard’s switching rules to move between normal, tightened, and reduced inspection where appropriate
- Nothing is free in industrial statistics, though, and the cost of less inspection is a higher producer’s risk of rejecting lots at the AQL. A c=0 plan should therefore be used only when quality is far better than the specified AQL.
- Generate an operating characteristic (OC) curve that compares the protection from the c=0 plan to that of the original ANSI/ASQ Z1.4 plan to gain the customer’s agreement for the use of a c=0 plan.
Attendees will also receive an Excel spreadsheet that shows the operating characteristic (OC) curve for a c=0 plan and compares it to the original ANSI/ASQ Z1.4 plan. Attendees can replace the example’s specification with their own.
Who Should Attend:
- Quality Managers
- Quality Inspectors
- Quality Technicians
- Quality Engineers
- Engineering Departments