A Road Tanker Scheduling System

• Description : A Road Tanker Scheduling System

• Problem: To improve the speed, consistency and quality of delivery schedules minimising distribution costs whilst satisfying customer delivery requirements and adhering to all regulations and procedures.

  The task was originally carried out by human schedulers but since the time available to produce schedules is limited the quality was greatly dependent on the skill of the individual and the pressure of other work. Furthermore it was very difficult to ensure that an optimum solution was retained if late orders or deliveries had to be accommodated at short notice.

• Solution: The solution was to assist the human schedulers by providing a computer based scheduling application which understood the legal requirements for drivers, the company standard policy, the requirements of the clients and the preferences of the drivers. This scheduler provides a delivery schedule which meets all stated criteria at minimum cost but allows the human schedulers to override any soft constraints and make partial assignments. It is seen as a tool to assist the schedulers rather than replace them, giving the company the most consistent, efficient and cost-effective mechanism for ensuring that delivery requirements are met.

• Main Features: the system provides (i) a fully auditable trace of adherence to working regulations, quality and customer delivery targets, (ii) a facility to assess the costs of alternative working practices and (iii) a service which produces consistent near-optimal solutions through:
  • explicit representation of vehicle distribution constraints (i.e., operating regulations and physical compatibilities).
  • explicit representation of operating preferences (e.g., drivers normally use own vehicles)
  • predictive and reactive scheduling
  • optimisation
  • interactive scheduling

• Technical Details:
  • The system runs under MS-Windows on a PC.
  • Ilog Solver, a constraint management software tool, and the Microsoft Access database are used.

• Development Effort: The total effort for the project is in excess of 1 man year.