Webinar On "Sequential Sampling to Reduce Inspection Costs"
Thu, Oct 4. 1:00PM - 4:00PM
ANSI/ASQ Z1.4 (formerly MIL-STD 105) is a generally accepted sampling standard for pass/fail data. This webinar will show that, while the standard's double and multiple sampling plans reduce the amount of inspection, minimal inspection can be achieved with sequential sampling; a process in which the consecutive sample sizes are 1. Attendees will learn how to convert an ANSI/ASQ Z1.4 plan into a sequential sampling plan that provides comparable protection against poor quality, and how to communicate this to the customer.
Attendees will learn how to use ANSI/ASQ Z1.4, including definition of the plan based on (1) the lot size, (2) the sampling level, and (3) the acceptable quality level (AQL), and also the switching rules for normal, tightened, and reduced inspection.
Attendees will learn (and a pre-programmed spreadsheet will be provided to help) how to convert the ANSI/ASQ Z1.4 plan into a sequential sampling plan, and also how to tabulate the sequential plan in a dozen or fewer rows to make it easy to deploy and use on the shop floor. This addresses the traditional administrative obstacle to use of sequential plans, namely, the need for a table with a hundred or more rows—one for each item that is inspected.
The webinar will also show how to calculate the operating characteristic (OC) curve for the sequential plan to demonstrate to customers that it has the same chance of rejecting a lot at the rejectable quality level (RQL) as the original ANSI/ASQ Z1.4 plan. (ANSI/ASQ Z1.4 plans do not have formal RQLs but we pretend, for computation purposes, that the RQL is the nonconforming fraction at which the plan has only a 10% consumer's risk of accepting the lot.) The average sample number (ASN) will meanwhile be consistently lower than that of the traditional plan's sample size, and even the ASN of the double and multiple sampling plans.
Areas Covered in the Session :
Inspection is a necessary but non-value-adding activity; the less we can do while continuing to meet customer requirements, the better.
How to use ANSI/ASQ Z1.4
Conversion of an ANSI/ASQ Z1.4 plan into a sequential plan
Who Will Benefit:
Manufacturing and quality engineers, technicians, and inspectors with responsibility for inspections that involve quantitative measurements of parts.
William A. Levinson, P.E., FASQ, CFPIM, is the owner of Levinson Productivity Systems PC. He holds professional certifications from the American Society for Quality, APICS, and Society of Manufacturing Engineers.