How to decide to use single level or multilevel BOM?

Dear all;

             Hope you are you well. We are working now in implementing ODM in manufacturing company. i need your help in deciding which type of BOM i will use, single level or multilevel?. i know this depend on the business and manufacturing process itself, but this is very confusing. we don't need to make any physical inventory for the shopfloor, but in the same time we need to know the WIP value at any time. Also,  we have 9 production process, but the relation beteen the finished product and the first subassembly is not direct this means when you make a job order for