Standard cost vs Unit cost and BOM Totals

We are using 3.60 and are creating BOMs and using Average Cost. Sometimes the Standard Cost for the individual units within the BOM do not add up to the sum of these parts in the BOM. In addition, sometimes the Unit Cost for the individual units within the BOM do not add up to the sum of these parts in the BOM. Also, the Unit Costs do not agree with the Standard Costs. Just need a few reasons why the differance in costs can occur between the individual parts not adding up to the BOM costs. I have Recalculated costs in the Assembly list. There are no BOMs within BOMs. Thanks.

Just to give a little more info, I set up a BOM and used existing two parts. The averge cost and standard costs equalled each other after Calculation the Standard Cost. Everything fine. Next, I issued a po to bring in ten units of each part. The parts used the same po price as the standard cost. Then five of the the units for each part were transfered to the BOM through the BOM purchase journal. The transfer worked fine but when I recalculated the BOM cost, the Standard Cost doubled and the Average cost remained correct! Hopefully this helps…

I think you are confussing which costs you are using. You need to clearly understand the costing methods for each of your components and finished product. If the finished good is at standard costs, then the costing method of the components has no effect what so ever on the final cost.