A Three-Stage Optimization Algorithm for the Stochastic Parallel Machine Scheduling Problem with Adjustable Production Rates

Table 2

The computational results under normal distributions.

Size (𝑛,𝑚)	TSA			PSO-SA
	Best	Mean	Worst	Best	Mean	Worst
𝜃=0.1
100,10	1.000	1.049	1.093	1.013	1.044	1.086
200,10	1.000	1.022	1.089	1.010	1.034	1.089
300,10	1.000	1.013	1.086	1.016	1.045	1.084
300,15	1.000	1.012	1.039	1.008	1.014	1.045
400,10	1.000	1.024	1.083	1.007	1.022	1.038
400,20	1.000	1.024	1.054	1.010	1.032	1.069
500,10	1.000	1.022	1.045	1.011	1.029	1.072
500,20	1.000	1.026	1.079	1.012	1.048	1.098
600,15	1.000	1.014	1.059	1.028	1.036	1.087
600,20	1.000	1.023	1.037	1.021	1.039	1.078
Avg.	1.000	1.023	1.066	1.014	1.034	1.075
𝜃=0.2
100,10	1.000	1.010	1.097	1.019	1.073	1.103
200,10	1.000	1.015	1.043	1.017	1.040	1.112
300,10	1.000	1.007	1.034	1.009	1.050	1.130
300,15	1.000	1.005	1.010	1.017	1.035	1.066
400,10	1.000	1.023	1.038	1.039	1.044	1.087
400,20	1.000	1.034	1.050	1.034	1.051	1.072
500,10	1.000	1.016	1.035	1.033	1.057	1.088
500,20	1.000	1.014	1.065	1.021	1.049	1.116
600,15	1.000	1.027	1.056	1.037	1.074	1.089
600,20	1.000	1.031	1.084	1.038	1.055	1.111
Avg.	1.000	1.018	1.051	1.026	1.053	1.097
𝜃=0.3
100,10	1.000	1.016	1.082	1.007	1.055	1.106
200,10	1.000	1.026	1.053	1.017	1.066	1.102
300,10	1.000	1.044	1.069	1.006	1.048	1.087
300,15	1.000	1.009	1.038	1.035	1.057	1.098
400,10	1.000	1.018	1.063	1.034	1.078	1.127
400,20	1.000	1.017	1.022	1.024	1.048	1.086
500,10	1.000	1.025	1.047	1.049	1.086	1.133
500,20	1.000	1.016	1.069	1.011	1.078	1.091
600,15	1.000	1.013	1.072	1.048	1.058	1.127
600,20	1.000	1.031	1.072	1.015	1.068	1.122
Avg.	1.000	1.022	1.059	1.025	1.064	1.108