We consider an asynchronous system with transitions corresponding to the instructions of a computer system. For each instruction, a runtime is given. We propose a mathematical model, allowing us to construct an algorithm for finding the minimum time of the parallel process with a given trace. We consider a problem of constructing a parallel process which transforms the initial state to given and has the minimum execution time. We show that it is reduced to the problem of finding the shortest path in a directed graph with edge lengths equal to 1.