To fulfill various customer demands by the same group of machines, flexible machine systems (FMS) are commonly used in fabrication facilities with heavy investment. FMS are computer-controlled systems consisting of several stations where each station specializes in particular operations with an appropriate transport system for the movement of products. In some wafer fabrication facilities, wafers are transferred between the load ports of machines within a bay via an automated guided vehicle (AGV). Multiple transportation tasks are required to be performed in time by the vehicle in order to secure the production schedules. The intra-bay vehicle scheduling problem is studied in this paper, which is strongly NP-hard. A heuristic search approach is proposed, incorporating two heuristic rules. Computational experiments show the effectiveness of the approach.