Many of the papers listed in Table 6 also provide performance evaluation of the different batching algorithms using simulation. It is however difficult to draw general conclusions since the performance depends heavily on factors such as storage location assignment policies, routing policies, the structureof orders, storage systems, and the maximum batch size. A comprehensive study that considers all the above factors and the various batch construction heuristics has not been published at this time. A few results have been published where two policy classes are studied jointly, for example, de Kosteret al. (1999) evaluate batching and routing algorithms together, and Ruben and Jacobs (1999) evaluate batching algorithms with different SLAP policies.