Statistical Techniques for Reducing the Experiment Time in Reliability Studies

This paper is concerned with a study of the advantages and disadvantages of three statistical techniques for reducing the average duration of life tests. These techniques are: 1. Increasing the initial number of units on test. 2. Using a replacement technique. 3. Using a sequential procedure. To show the advantages of each of these techniques, we shall consider the problem of deciding which of two processes has the smaller failure rate. Three different types of procedures for making this decision will be considered. They are: R i , A nonsequential, nonreplacement type of procedure R 2 , A nonsequential, replacement type of procedure R 3 , A sequential, replacement type of procedure Within each type we will consider different values of n, the initial number of units on test for each process. The effect of replacement is shown by comparing the average experiment time for procedures of type 1 and 2 with the same value of n and comparable probabilities of a correct selection. The effect of using a sequential rule is shown by comparing the average experiment time for procedures of type 2 and 3 with the same value of n and comparable probabilities of a correct selection. ASSUMPTIONS