Sage 200 Standard - BOM allocation

We need to be able to allocate stock from a BOM and build when the item is physically built. Without this function we have only 2 options (1) build at the start but if the physical build is then not for a few weeks the physical stock quantities for all components in the assembly is wrong which is very confusing, but at least component shows the demand for purchasing, or (2) build the item when the item is physically built but then none of the components are allocated so again we don't know what stock we have and demand for purchasing doesn't work. This is causing us a significant issue and is VERY disappointing this is not possible. Can we have the allocation from BOM in 200 Standard please.