“…These cases are assumed to be 1=2=3=4=1 for case one, 1=1, 2=2, 3=3, and 4=4 for case two, and 1=4, 2=3, 3=2, and 4=1 for case three, correspondingly. In the approximation calculation, we apply an average concurrency approach described in (Jittawiriyanukoon, 2019) and compute upon mathematic equations listed in section 2. Simulation and approximation results from experimental three cases are summarized in the following Tables 1-6.…”