Logistical planning with the help of simulation modeling: A case study

This article gives an overview of the combined use of object-oriented programming and simulation, with the objective of analysing and planning the logistic functions of a firm. An object-oriented simulation approach is used to evaluate the reception and distribution function of a courier firm. Both the reception of and operations (sorting) on the parcels in the plant were simulated. The first objective of the firm was to analyse the productivity of the conveyor belts and workers in the sorting plant of the courier firm. The firm's utilisation of most of its resources is fairly good, but it is possible to obtain a more efficient process by restructuring its activities. Results from the simulation study showed an imbalance in the capacities of the workstations. Some of the workers, especially those to the end of the conveyor belts, spent almost all of their time waiting for parcels to reach them, while those at the beginning were working at maximum capacity. This is mainly due to the layout and structure of the system. The biggest bottleneck in the system was the capacity of the coupling between two of the conveyor belts. The conclusion was that the firm should seriously consider redesigning the plant. This is the first computer model of the firm's business activities that can be used as a planning tool, and fills a gap in its current planning function. This simulation can be used to determine where and how workers should be applied in the sorting process. The complete simulation model reaches its potential when used as a strategic operational tool, by forecasting the expected results from changing operations and plant layout. A new plant layout has been proposed to the firm, which the model shows to result in substantial improvements in the productivity of the workers, allowing a reduction in their numbers.