指数寿命可靠性增长评估中增长因子的确定方法

Determination of Growth Factor in Reliability Growth Evaluation with Exponential Life

对于延缓纠正模式的可靠性增长试验,阶段内产品的寿命服从失效率为常数的指数分布,而阶段间的可靠性有阶跃增长,通常考虑以增长因子进行阶段间的信息传递,增长因子的确定成为关键。首先分析常用的ML-Ⅱ确定方法的局限性,提出改进的ML-Ⅱ方法,并对阶段末的可靠性作出Bayes评估。最后仿真示例表明了改进方法的有效性。

For the reliability growth tests with delayed-fix mode, the life in a stage can be assumed to follow the exponential distribution with a constant failure rate. However the reliability between stages has a growth. Usually, growth factor was used for the information transfer between stages. Thus the determination of growth factor becomes very important. The limitation of ML-Ⅱ method commonly used is analyzed and a modified ML-Ⅱ method is given. Then Bayesian evaluation method of reliability is deduced. At last, the example shows the feasibility of the modified ML-Ⅱ method.