In BellHawk, we can track materials as they flow out of one operation and into the next. This has the benefit that not all the work-in-process materials (WIP) have to travel as one batch. We can record parts flowing through a sequence of operations and track some parts being reworked in out-of-route operations, all at the same time. This is much more efficient than forcing the parts to travel as one batch, just to keep track of all the parts.
This does, however, bring with it the part numbering issue. As we record a part out from a work-order operation, we need to identify its part number. This is fine for the last step in the operation, where we use the part number of the product being made but what about the intermediate materials. If we have to invent a part number for each intermediate WIP part, we rapidly end up with a parts number explosion and a lot of work putting these all into BellHawk.
Instead of that, in BellHawk, we recognize that these intermediate WIP materials are on their way to being the finished part and may look like the finished part but have not yet completed all their operations. As a result, we use the same part number as the finished part but we use a WIP flag to indicate whether these are finished parts or not so they will not be confused as being in finished goods inventory.
This avoids the problem of assigning a separate part number for each intermediate material but, by tracking which operation on which work order the parts came from, we can easily track the status of this WIP material.
Please note that WIP materials are different from intermediate materials that have their own part number. For example, we may mix a batch of materials in one work order and then package it in another. Each of these work orders may have a sequence of operations, with their own WIP flagged materials but the finished mix is a completely separate intermediate product, with its own part number, that may be packaged into a number of finished products, each with with their own part numbers.
BellHawk also has the concept of an item number for the route separate from the part-out resources produced by each operation on the route. This is to enable the recording of multiple different parts out from an operation. For example, we may have an item number with a route to make a left and right pair of safety glass lenses. The route may include operations such as molding, cutting, polishing, and inspection. At each step in the route, except for the last, the left and right lenses are treated as a pair, using the item number for the route with the WIP flag on. At the last operation, the left and right lenses can be recorded out with separate finished goods part numbers. Also, in the first molding step, the scrap plastic from this operation can be periodically recorded out as scrap plastic to be recycled into reground plastic pellets, with its own part number.
This concept of recording WIP materials applies whether the WIP materials are an individually barcoded assembly, or a quantity of parts in a barcoded container, or even untagged boxes or other materials at a location.