Coba jelasin Bottom–up design dari Manajemen siklus produk dong

Bottom–up design (CAD-centric) occurs where the definition of 3D models of a product starts with the construction of individual components. These are then virtually brought together in sub-assemblies of more than one level until the full product is digitally defined. This is sometimes known as the review structure showing what the product will look like. The BOM contains all of the physical (solid) components; it may (but not also) contain other items required for the final product BOM such as paint, glue, oil and other materials commonly described as 'bulk items'. Bulk items typically have mass and quantities but are not usually modelled with geometry.

Bottom–up design tends to focus on the capabilities of available real-world physical technology, implementing those solutions which this technology is most suited to. When these bottom–up solutions have real-world value, bottom–up design can be much more efficient than top–down design. The risk of bottom–up design is that it very efficiently provides solutions to low-value problems. The focus of bottom–up design is "what can we most efficiently do with this technology?" rather than the focus of top–down which is "What is the most valuable thing to do?"