Abstract
During an operation a mechanical system cost is a function of the time operation. Until now, we have taken into account the variation of economical factors as a function of time. The present work tries to import fuzzy logic in order to determine a variable model of economical factors as a reference to stillness, lubrication, repair of the mechanical systems and the variation of the operation tensions as for time. Which important levels are the mechanical systems so time operation affects the equivalent cost. The fuzzy logic model which was established, have data which was measured in the past and these data make a model with polynomial method, which doesn’t gives trustworthily results. The use of computer software is important because this method is variable as a function of cost and time.
