Degradation‐based burn‐in with preventive maintenance

As many products are becoming increasingly more reliable, traditional lifetime‐based burn‐in approaches that try to fail defective units during the test require a long burn‐in duration, and thus are not effective. Therefore, we promote the degradation‐based burn‐in approach that bases the screening decision on the degradation level of a burnt‐in unit. Motivated by the infant mortality faced by many Micro‐Electro‐Mechanical Systems (MEMSs), this study develops two degradation‐based joint burn‐in and maintenance models under the age and the block based maintenances, respectively. We assume that the product population comprises a weak and a normal subpopulations. Degradation of the product follows Wiener processes with linear drift, while the weak and the normal subpopulations possess distinct drift parameters. The objective of joint burn‐in and maintenance decisions is to minimize the long run average cost per unit time during field use by properly choosing the burn‐in settings and the preventive replacement intervals. An example using the MEMS devices demonstrates effectiveness of these two models.