Help is also mentioning the following, that in product structure I can assign the low level codes. You can assign a low-level code to each part in the product structure or the indented BOM. The top final assembly level is denoted as level 0 - the end item. The higher the low-level code number, the lower the item is in the hierarchy. For example, end items have low-level code 0, and the item parts that go into the assembly of the end item have low-level codes 1, 2, 3, and so on. The result is the planning of component parts coordinated with the requirements of all higher-level part numbers. When you calculate a plan, the BOM is exploded in the planning worksheet, and the gross requirements for level 0 are passed down the planning levels as gross requirements for the next planning level. So where do I do this.