The goods handling process in a warehouse divided into three macro-areas has been modelled on the basis of the location of the goods on the shelves and the way they are handled (pallet area handled by forklifts, automatic area handled by stacker cranes and manual area handled by floor operators).

Each area is characterised by a number of available resources and an hourly productivity index. The unit of measurement referred to the goods handled is the handling order line, which together constitute the order itself (on average, for each order 9 lines have been assumed). The frequency of arrival of handling requests is governed by a probability function acting on the number of total daily requests (fixed at an average value for each day of the week).  The time unit corresponding to a simulated step is the hour and the warehouse operating time is defined on the interval 7-19 on Mondays to Fridays and on the interval 7-14 on Saturdays.

The area of the warehouse affected by each movement is determined probabilistically on the basis of a historical data series. The aim of the simulation is to efficiently dimension the internal warehouse resources by evaluating the behaviour of the system on the peaks of incoming requests.