Although having the benefit of simplicity, manual methods of vehicle scheduling tend to be inefficient. The task is mentally taxing and schedules are prone to making mistakes, resulting in a sub-optimal schedule. This has given impetus to the development of computerised models for vehicle scheduling.
The advantages of computer based scheduling include speed, accuracy and the potential to interface vehicle scheduling models with other components of the overall management information system (e.g. stock control, invoicing, sales analysis). The main disadvantages are that the software is complex, and is therefore expensive, and, of course, it requires a computer with a maths co-processor to run the model. Another disadvantage is that because of the complex algorithms involved in the model, most managers will not understand it well enough to correct data input errors. That is, the non-mathematical manager will fail to recognise errors in the schedules produced by the model. Robson3 however, puts a strong case for computer - based vehicle scheduling when he says that:
“Measured against present costs the likely benefits of computerised scheduling are still very significant. On a global scale it has been estimated that some 25% of the $4,000 million spent each year on distribution could be saved by the increased utilisation of vehicles.”