Accelerated life testing for speedier product development: problems and strategies

Abstract

The time spent from the conceptual stage to the final product development stage needs to be competitively small in order to be successful in today's market place. Working with fewer samples within fewer numbers of design iterations, reducing the time between two design iterations, and achieving higher reliability among such iterations are some of the main challenges of the product development process (PDP). Such common problems as well as some helpful strategies using accelerated life testing for speeder goal achievement at different stages of the PDP are discussed. Examples from the appliance industry are used to demonstrate the utility of these strategies. In this regard, goal specific accelerated life tests (ALT) at component and subsystem levels were designed. A key design specification is for the product to performance under the specified operational conditions over the expected life. In the first phase of the design, time-compressed ALT and highly accelerated life tests (HALT) were used. Based on the test results, further design iterations were implemented with HALT and reliability growth was compared with previous design iterations. Test fixtures were designed as needed to simulate the normal operating levels and to accelerate specific failure modes identified from the failure mode and effect analyses. Failures, from the customer's perspective such as home tranquility disturbance were captured only during the normal level of operations. Weibull probability plots were successfully used in the data analyses, highlighting failure modes and monitoring reliability growth. In conclusion, the tests and ensuing analyses were effectively and efficiently used to increase the degree of reliability improvements between two design iterations and also to reduce the total number and cost of design iterations that resulted in a shorter design cycle