During my manufacturing course I always explain that routings in Business Central are not strictly associated to a single item, but can be used on different ones.
This can be very useful for companies using the same machines/operations to make different products. For example, we can make two different models of a bicycle by mounting on them two different bells or lamps, so that the final product is using two different BOMs but the same routing.
In this situation we must pay attention to base unit of measure of the product. Let me give you an example.
Suppose to have this very easy item
Suppose that unit cost of Item A1 is simply 1,00€ for one piece. Now let’s introduce the routing
Supposing the Unit Cost being 1,00€ / minute, the final standard will be 2,00€ for each piece of Item A.
Now, let’s create the same Item, but let’s use as Base Unit of Measure a Box, and suppose that a Box is made of 10 PCS
Now, if we use the same routing as before, the Unit Cost changes and becomes 11,00€ for each BOX, so 1,10€ for each piece:
This is due to the fact that in this case the minute we spend in the Run Time is for each BOX and not for each piece.
When we create routings and we associate them to different items, we have always to check that they’re using the same base unit of measure, otherwise the standard cost calculation will be wrong.
This very particular situation can happen when you work with items using weight or volume unit of measures, like Kg, Liters and so on. The example above is very rare and was used just to focus the attention.