A review of design and control of automated guided vehicle systems <s> Performance criteria <s> An important factor in the design of automated guided vehicle systems (AGVS) is the flow path design. This paper presents an approach to determining the optimal flow path. The objective is to find the flow path which will minimize total travel of loaded vehicles. The problem is formulated as a zero-one integer program. Examples are presented to demonstrate the approach. <s> BIB001 </s> A review of design and control of automated guided vehicle systems <s> Performance criteria <s> SUMMARY This paper describes an alternative formulation of the AGV flow path layout (FPL) problem which was first formulated by Gaskins and Tanchoco (1987) as a zero-one integer programming problem. A computationally efficient procedure is proposed which is based on the branch-and-bound technique. An algorithm for satisfying the reachability condition for nodes in the AGV flow path network is also presented. A simple illustrative example is discussed to demonstrate the procedure, and a more complex problem is also given. <s> BIB002 </s> A review of design and control of automated guided vehicle systems <s> Performance criteria <s> Asynchronized automated material handling systems, e.g. automated electrified monorail systems and automated guided vehicle systems, have been playing important roles in manufacturing. Reliability becomes a critical issue as manufacturing enterprises are moving toward automation. In the past, reliability tissue has not been analysed explicitly for these types of systems. In this research, a new measure was proposed to specify reliability. A mixed integer programming model was developed to design flow paths for a special class of material handling systems, i.e. single-loop dual-rail systems. The model can be used to design systems with higher reliability. The model and application procedure in design and analysis were demonstrated through two case studies. <s> BIB003 </s> A review of design and control of automated guided vehicle systems <s> Performance criteria <s> An optimal flow path layout (FPL) design method is introduced as a handy tool for an automated guided vehicle (AGV) system planing stage. The problem is analysed and formulated by linear mixed-integer programming. A procedure based on the branch-and-bound depth-first search technique is proposed to solve the FPL problem. The procedure is implemented as an efficient computer program and yields an optimal solution in a small number of iterations. Using the transportation model for calculating the required and optimal flow of empty vehicles, system balance is achieved. Finally, two examples are given. A simple illustrative example is discussed to demonstrate the procedure, and a realistic FPL problem with 23 nodes, 66 arcs and nine pick-up/delivery stations is solved. <s> BIB004 </s> A review of design and control of automated guided vehicle systems <s> Performance criteria <s> A construction algorithm is suggested to design guide path networks for automated guided vehicle systems (AGVSs). This study uses the total travel time, including waiting and interference time, of vehicles as the decision criteria for determining the direction of path segments on unidirectional guide path layouts. The Q-learning technique is applied to estimate the travel times of vehicles on path segments. Computational experiments were performed to evaluate the performance of the proposed algorithm. The simulation results showed that the proposed algorithm is superior to Kim & Tanchoco's (1993) algorithm in terms of the average travel time, the interference time and the number of deliveries. <s> BIB005
An important question is which performance criteria are most important for the guide-path design problem.  describes several important performance criteria for automated guided vehicle systems such as vehicle travel time, vehicle utilization, queue length, and material handling cost. The most common performance criterion in guide-path design is minimizing the total vehicle travel distance corresponding to a given layout and flows BIB001 BIB002 . BIB004 include both the vehicle loaded and empty travel time in the objective function. BIB005 use the total vehicle travel time (including the loaded and empty vehicle travel and waiting time caused by congestion or vehicle interferences) as the objective function. Several authors use multiple objectives. consider the travel cost and the cost of each path segment. BIB003 use the total vehicle travel time and the trip failure rate as performance measures for their model.  uses the required number of vehicles and the guide-path length to measure the system performance. Generally, multi-criteria objective functions lead to a better solution quality. The next three sections review the design problem for the three most important guide-path systems in literature. The literature does not clearly indicate when and where a specific type should be selected, but based on the system requirements, characteristics of facilities and of each guide-path system, decision makers can select one of them for their system.