One of the powerful tools for generating the joint distribution functions of dependent variables by the marginal distribution functions is copula. According to the definition of the copula, very criteria are introduced, using which most of the dependencies of the variables can be expressed. recently, with increasing use of science in the manufacturing industry, it is important to examine the characteristics of the systems. In analyzing the lifetime of components of system , it is necessary to determine the multivariate distribution function of the structure-function of the system.
