When to stop testing software? A fuzzy interval approach

the experience of many programmers shows that it is actually impossible to extract all the faults from system-type software, that is commonly involved in resource contention, or from the programs with a sophisticated user interface. Also, it is necessary to estimate the time interval during which the remaining faults will not influence the program. This problem is vital for estimating the cost of the software project. At present about three dozen statistical models (called software reliability models) are used to get such estimates. However, these statistical models lack convincing theoretical-explanation. They are semi-heuristic, and often look like curve-fitting. In this paper, we consider a fuzzy approach to program testing. We formulate the problem of choosing the best fuzzy software reliability model as a mathematical optimization problem, and solve this problem