A Bill of Materials (BOM), is essentially a list of products that are required to produce another product. You can think of it like the list of ingredients for a recipe. Odoo needs to know what materials are required for us to produce this Class of 2017 T-shirt product.
In complex products, a bill of materials can be nested. For example, it may take many products to make a sub-product, and then several sub-products to make a final product.
Don't let nested BOMs intimidate you. Once you understand how a simple BOM is processed, you will more easily see how you can group parts together. Think about grouping more complex BOMs by assembly and workcenters. This makes it easier to see your inventory in real time, ...
