provide a new model for evaluating general multi-stage series systems ‎with‎ undesirable and non-discretionary factors

The presence of undesirable and non-discretionary factors in general multi-stage systems is one of the challenges of evaluating these systems. this challenge is multiplied when these factors are present in the system at the same time. in this article, a new model is presented for evaluating general multi-stage ‎series systems with these factors. the general idea of this mode‏l is ‎how ‎to ‎choose‎ the contraction and expansion parameters, finally the results are examined with a numerical example.