A general model of heterogeneous system lifetimes and conditions for system burn‐in

Abstract

Burn-in is a technique to enhance reliability by eliminating weak items from a population of items having heterogeneous lifetimes. System burn-in can improve system reliability, but the conditions for system burn-in to be performed after component burn-in remain a little understood mathematical challenge. To derive such conditions, we first introduce a general model of heterogeneous system lifetimes, in which the component burn-in information and assembly problems are related to the prediction of system burn-in. Many existing system burn-in models become special cases and two important results are identified. First, heterogeneous system lifetimes can be understood naturally as a consequence of heterogeneous component lifetimes and heterogeneous assembly quality. Second, system burn-in is effective if assembly quality variation in the components and connections which are arranged in series is greater than a threshold, where the threshold depends on the system structure and component failure rates.

Optimal burn-in for maximizing reliability of repairable non-series systems

“…(1) reduces to the model of Kim and Kuo [17], which includes many burn-in models such as mixed distributions [11], the IBM model [23], and others [1,3,4,9,14,15,26,29]. Kim and Kuo [14,17] showed analytically that the variance in number of assembly defects in the series-connection plays a critical role in the development of infant mortality failures, assuming that F Ã i;b i ðtÞ ¼ F i;bi ðtÞ and f(mjm) is a multinomial distribution. Kim and Kuo [15] studied the optimal burn-in time of a repairable series system to minimize the cost structure when all components have decreasing failure rates.…”

A lifecycle cost model considering both component and system burn-in for operationally unrepairable systems

“…Whitbeck and Leemis (1989) introduce a pseudo-component into the reliability structure to represent damage that occurs during the assembly process. More recently, notable works by Kim and Kuo (2003) discuss the conditions where system burn-in is required under variations in assembly quality. Kim and Kuo (2009) build on this and maximizes reliability for a non-series system by optimizing burn-in durations.…”

Burn-in policies for products having dormant states

“…The items that fail during the burn-in procedure will be scrapped or repaired; only those that survive the burn-in procedure will be considered to be of good quality. Burn-in could be performed on the basis of a system (see [8,9]) or an individual component (e.g., [10,11]). The systems might be electronic systems such as circuit boards or mechanical systems including air conditioners, or subsystems like an aircraft electrical subsystem, and the components would be various types of chips, printed circuits, condensers, fans, and so forth.…”