About Scheduling Strategies
Infor Production Scheduling uses both backward (pull) and forward (push) scheduling techniques.
- is demand-driven. You know what you have to deliver based on your orders. Therefore, you identify required preceding steps or batches and schedule them to enable the delivery. In other words, you know what to produce but want to know the required lead-time and feasible scheduling for it.
- is supply-driven. You know what you have in your inventory but want to determine when and what to make with it. This is especially useful when dealing with divergent product lines. For example, determining where you can produce different variations of a product and when you have a large supply that needs to be processed, even before there are orders.
If one of the stages has less than the required capacity, it will limit output and thus becomes the production bottleneck. When such a bottleneck occurs, it is a common practice that the processes for that particular stage are scheduled first to achieve an optimal solution. You start from that bottleneck and create the inflows required for it, i.e., trigger the activities to provide the required inputs. Then, create the outflows needed in the stages that come after it.
Forward or push scheduling strategy is used in situations in which you can produce different variations of a product. First, you define what ingredients are available. Second, you define the sequence of steps to follow to arrive at specific end products. You are effectively scheduling batches forward to use existing inputs. You are therefore pushing what you have down a production path, thus forward or push scheduling. This scheduling approach is used together with pull scheduling to deal with production bottlenecks. First, schedule activities for the bottleneck stage to achieve an optimal solution. Second, create inflows for the bottleneck stage, i.e., (backward) schedule the steps to provide the required inputs. Third, schedule process batches to create products using the available inputs from the bottleneck stage, i.e., create outflows needed in the stages that come after the bottleneck. The push scheduling strategy underlies the create outflow function.
Here is another example of using forward scheduling. You process vegetables that are harvested once a year. They need to be canned quickly, but there are no existing orders. You can push it forward to be canned as bright stock (white stock) and then labeled as the orders come in.
Backward scheduling or pull scheduling is the main strategy used by Infor Production Scheduling to arrive at an optimum schedule. First, you identify what is to be produced. Second, you identify the steps needed to produce the items. You effectively schedule backward in time, working from the end product or final steps backward to the ingredients or preceding steps. It is, therefore, called backward or pull scheduling strategy. You schedule the required preceding batches as is needed to most efficiently make what you want to produce.