Scheduling which products to produce on a machine is not trivial. There are lots of factors that influence which parts should be produce and by which date. Let’s assume we plan the schedule of the hot mill, i.e. which ingots (alloy type, width, heat treatment, etc.) should be rolled and in which order.

On the highest level, the schedule is determined by the customer’s sales orders. It’s not uncommon that more sales orders are processed than the factory can produce. This is partly due to the sales team not having a clear insight into the capacity of the plant. Although the data is technically in the MES or ERP systems, it’s not processed and communicated.

Once a plant knows what orders to produce and by which date, the fine scheduling can begin. Fine scheduling involves planning which ingots to roll on the hot mill in the next one to three days. Here the physical properties of the process take the center stage: alloy, ingot width, heat treatment, etc. Normally, computer systems can calculate the optimal order. However, because not all scheduling problems are mathematically solvable, e.g. when the orders to produce exceed the plant’s capacity, human decisions are always necessary.

Unfortunately, these decisions are rarely data driven.