Setting up an ERP system for manufacturing is complicated and sometimes you forget parameters when you setup some master data which will result in a function not working well. For example if you create a production order and you try to operations schedule and get an error message not enough capacity could be found. Then there is a number of possible reasons for this. The SCM team wrote a good blog on this a while back so it’s worth looking through this for your situation.
If you are doing operations scheduling then there is a good indicator it’s an issue with the resource group so you want to check that first. Here is a quick walk through of an example.