The Efficiency of Variance Reduction in Manufacturing and Service Systems: The Comparison of the Control Variates and Stratified Sampling

Table 4

The variances of AWT.

Levels	1.Exponential	2.Uniform	3.Triangular	4.Normal
1.Control variates	0.000010	0.0715000	0.0000398	0.0000155
	0.000780	0.0063840	0.0010400	0.0001010
	0.039400	0.0000188	0.0124800	0.0000254
	1.503000	0.0824800	0.0007170	0.0000939
2.Stratified sampling	0.105	0.395	0.432	1.541
	1.012	0.492	0.386	1.224
	0.972	1.415	0.664	1.238
	2.430	0.162	0.531	1.127