Sequential Lot Acceptance Test Calculator

A sequential lot acceptance test calculator was recently added to the Reliability Analytics Toolkit.  Sequential testing is a very efficient way of demonstrating lot quality with relatively few samples.  The calculator tests the mean of the binomial distribution and can be applied where each unit is classified into one of two categories, good or defective. The underlying technique, developed during World War II, is based on the work of mathematician Abraham Wald while at Columbia University’s Statistical Research Group.  Continue reading

Sequential Reliability Test Calculator

A Sequential Reliability Testing Calculator was recently added to the Reliability Analytics Toolkit. Sequential testing often provides a more efficient method to verify equipment reliability achievement. Really “good” equipment will be accepted much quicker and really “bad” equipment will be rejected much sooner, often resulting in fewer test hours needed than using a military handbook 781 fixed length reliability test. The tool provides the ability to plan a sequential reliability demonstration test for verification of equipment mean time between failure (MTBF) if it can be assumed that the equipment follows an exponential failure distribution (i.e., constant failure rate). Continue reading