Heuristics on optimal vehicle routing for Permutation Circulation-type Vehicle Routing System with short-cut

We treat with an automated material handling system which we call Permutation Circulation-type Vehicle Routing System with short-cut (denoted PCVRS). In the PCVRS a fleet of vehicles unidirectionally and repeatedly circulates on a single loop, and carry items to stations which are placed along the loop. One of the important issues for the PCVRS to be efficiently operated is to minimize interference or blocking between vehicles, which may deteriorate system performances. We analyze three vehicle routing rules which allocate jobs to station and show effect of optimization for a real system by means of simulation.