5.2.1. Sequencing and routing for conventional multi-parallel-aisle systems
In a conventional multi-parallel-aisle system, the aisle structure limits the TSP state space, which greatly simplifies its solution. Ratliff and Rosenthal(1983) propose a polynomial-time dynamic programming algorithm to optimally solve this problem.
The algorithm depends on the following assumptions: parallel, narrow and equal aisles, a
single I/O point for the picker in the warehouse, the aisles connected by a cross aisle at each end, and the SKU locations given. Other authors have relaxed some of these assumptions and proposed different algorithms to deal with these complications.
These related results are summarized in Table 7, where Ratliff and Rosenthal (1983) is listed firstwith the assumptions they made and followed by the
other results that relax some of the restrictive
assumptions (see the problem setting column in
Table 7).with the assumptions they made and followed by the
other results that relax some of the restrictive
assumptions (see the problem setting column in
Table 7).