Optimization of Storage Location Assignment in Tier-To-Tier Shuttle-Based Storage and Retrieval Systems Based on Mixed Storage

Table 3

The simulation results of the maximum number of different varieties stored per location.

Maximum number of items per storage	Initial solution (s)	Optimum solution (s)	Algorithm calculation time (s)	Optimal solution improvement rate (%)
1	625770	539178	386	—
2	540618	441508	405	18.11
3	481098	408474	431	7.48
4	442852	387220	446	5.20
5	435614	375621	462	3.00
6	431027	371258	470	1.16
7	429945	369144	475	0.57
8	429122	368827	481	0.09

Optimal solution improvement rate (OSIS) is that the reduction rate of the optimal solution in this row is relative to the optimal solution in the previous row. Take the second row of data for example, .