Narrow Results

This paper presents a subjective safety and cost based modeling approach for evaluating safety requirements specifications in the study of safety-critical software. In the approach fuzzy set modeling and evidential reasoning are combined to assess both the safety associated with and the cost incurred in each option of safety requirements specifications. Both safety and cost estimates are combined to obtain the preference degree associated with each option of safety requirements specifications for selecting the best one. An example is presented to demonstrate the proposed approach for safety based on decision-making in safety requirements analysis of safety critical software development.

A fuzzy software reliability model is proposed where the time intervals between the software failures are taken as the fuzzy variables governed by a membership function. The model takes into account the following assumptions: new faults may be introduced into the software during debugging processes, the number of faults removed after a failure may be greater than one, and there is a growth of human experience during debugging. The model can be considered as an extension of the model developed by Cai, Wen and Zhang. An efficient algorithm is presented for estimating parameters of the model. The numerical examples validate the proposed model.