Interactive
A large number of operations are planned on an interactive basis that allows the scheduler to find the most effective routes. Actual demand is used rather than historical demand, and this provides the basis on which routes will be scheduled.
Schedules produced interactively can result in varied routes day by day. The reason for this is because computers can reconsider demand requirements and arrive at an original result every time it is used. One of the benefits of an interactive approach is that the scheduler is in a position to make changes to routes as they are required.
The following is an example of interactive scheduling:
When a new urgent order is received via a customer after the initial route has been planned. The scheduler can input the order manually and assign the new order to an existing route. The computer can check the route to see if the new order can be accepted. This amendment can be rejected for a variety of reasons, such as insufficient capacity left on the vehicle, insufficient time available and so on. As a result, the scheduler can use the computer to make sure that the order is only placed on a vehicle that is in a position to complete the delivery both legally and within the allotted service constraints.
Planning
The final type of scheduling and routing problem concerns the planning and measurement of the effect of a change. Again the use of computer technology can be used to test and simulate the effect of changing things like demand, vehicle availability and changes in legislation. This is commonly known as ‘what if’ planning.
The following is an example of a planning scheduling problem:
A third party contractor normally uses routing and scheduling computer packages to aid in response to invitations to tender for new business. The computer package will allow them to identify fleet and driver requirements and cost the operation accordingly.
A large manufacturer of soft drinks uses routing and scheduling computer packages to help in identifying the effects of using different minimum order sizes for its variety of products to its many different customers. Any reduction in the minimum order size will bring an increase in revenue but can be offset by the increased costs in delivery. This is because smaller orders have to be delivered.