A Two-Stage Queue Model to Optimize Layout of Urban Drainage System considering Extreme Rainstorms

Table 7

Results after ten operations of Case (, ) with stochastic and fuzzy features.

Test number	Layout		Fixed cost	Operation cost	Total cost	Queue length of surface water			Sojourn time in all queues			Total time
	Inlets	Pump stations				Min	Max	Mean	Min	Max	Mean
1st	64	4	2415.36	85.01	2500.37	66.07	70.32	68.20	3426.5	3882.3	3654.4	3882.3
2nd	64	4	2415.36	84.57	2499.93	66.03	70.35	68.19	3422.2	3885.4	3653.8	3885.4
3rd	64	4	2415.36	79.03	2494.39	65.30	70.16	67.73	3347.1	3864.3	3605.7	3864.3
4th	64	4	2415.36	77.35	2492.71	64.02	70.37	67.19	3216.9	3887.5	3552.2	3887.5
5th	64	4	2415.36	78.77	2494.13	64.52	70.18	67.35	3267.6	3866.2	3566.9	3866.2
6th	64	4	2415.36	82.61	2497.97	66.13	69.92	68.02	3433.2	3837.4	3635.3	3837.4
7th	64	4	2415.36	80.43	2495.79	64.63	70.17	67.40	3278.7	3865.1	3571.9	3865.1
8th	64	4	2415.36	79.36	2494.72	64.61	70.16	67.38	3276.5	3863.7	3570.1	3863.7
9th	64	4	2415.36	81.65	2497.01	65.56	70.18	67.87	3374.2	3866.6	3620.4	3866.6
10th	64	4	2415.36	78.42	2493.78	64.19	70.01	67.10	3234.9	3847.3	3541.1	3847.3
Min	64	4	2415.36	77.35	2492.71	64.02	69.92	67.10	3216.9	3837.4	3541.1	3837.4
Max	64	4	2415.36	85.01	2500.37	66.13	70.37	68.20	3433.2	3887.5	3654.4	3887.5
Mean	64	4	2415.36	80.72	2496.08	65.10	70.18	67.64	3327.78	3866.6	3597.2	3866.6