The locations of dwell points for idle vehicles in an automated guided vehicle (AGV) system determine the response time for pick-up requests and thus affect the performance of automated manufacturing systems. In this research, we address the problem of optimally locating dwell points for multiple AGVs in general guide-path layouts with the objective of minimizing the mean response time in the system. We propose a mixed integer linear programming (MILP) formulation for the problem. We also develop a generic genetic algorithm (GA) to solve the problem. The MILP models and the GA procedure are illustrated using a two-dimensional grid layout problem. Our computation study results show that the proposed GA procedure can yield near optimal solutions for these test problems in reasonable time.