The facility layout instances of the generalised travelling salesman problem
研究了在设施布局中设计循环路径和输入输出站以最小化总行程距离的问题，将循环覆盖每个工作中心至少一条等高线的布局视为广义旅行商问题实例，并开发了互补启发式方法。
In this paper, we provide new insight into the problem of designing loop flow-patterns and input-output (I/O) stations in a facility layout to minimise the summation of loaded and empty trip distances. The loop covering at least one contourline of each workcenter in a manufacturing facility layout is an instance of the generalised travelling salesman problem (GTSP). The shortest length solution to this GTSP provides a promising heuristic scheme to minimise the total loaded and empty flow in vehicle-based material handling. The sequence of the I/O stations alongside the loop also plays a significant role in determining the volume of the loaded and empty flow. The larger the set of candidate locations for I/O stations, the higher the flexibility in sequencing the stations. On this foundation, we define a new objective function of maximal-node-covering for our instance of the GTSP. By combining the characteristics of the shortest and the maximal-node-covering loops, a set of complementary heuristics are developed to design a loop and locate the I/O stations to minimise the total loaded and empty flow.