(1)where:This chapter includes the following sections:
Lloyd and Lipow (1962) considered a situation
in which a test program is conducted in N
stages. Each stage consists of a certain number of trials of an item undergoing
testing and the data set is recorded as successes or failures. All tests
in a given stage of testing involve similar items. The results of each
stage of testing are used to improve the item for further testing in the
next stage. For the kth
group of data, taken in chronological order, there are nk
tests with Sk
observed successes. The reliability growth function is then [6]:
(1)where:
Note that essentially, 
.
If the data set consists of reliability data, then Sk
is assumed to be the observed reliability given and nk
is considered 1.
