Figure illustrates the behavior of calculation time for ODE23s and ODE15s, depending on the SR tests in Table Insert Figure Depending on the SR, the calculation time for ODE solvers can become very high. This can be easily seen in Fig. where the ODE15s calculation time presents an exponential behavior. with SAS for this case study was 4.2864 × 10 !"# , with a computation time of 6.81365 s. This is a very significant result.