An Analytic Model for Design of a Multivehicle Automated Guided Vehicle System
提出一个分析模型，用于设计多车自动导引车系统，以补充现有非自动化物料搬运系统。模型将车辆池建模为M/G/c排队系统，并通过二进制整数规划确定哪些工作中心需要自动化配送及所需车辆数，目标是在平均等待时间不超过预定限制的条件下最大化系统效益。
We consider the problem of designing a multivehicle automated guided vehicle system (AGVS) to supplement an existing nonautomated material handling system. The AGVS consists of a pool of vehicles that deliver raw components from a central storage area to workcenters throughout the factor floor. The objective is to determine which workcenters warrant automated component delivery and the number of vehicles required to service those workcenters, to maximize the benefit of the AGVS, subject to a constraint that the average waiting time for material transport in the system not exceed a predefined limit. The pool of vehicles is modeled as an M/G/c queuing system and the design model is formulated as a binary integer program with nonlinear waiting time constraints, which are expressed by approximate queueing formula. We develop two different implicit enumeration algorithms to exactly solve the analytical model. We illustrate our model with an example of an actual AGVS design problem at Hewlett-Packard, and we present computational experience for other example design problems. We show how sensitivity analysis can be used to ensure that the analytical model yields an optimal solution to the design problem.