Product family with many variants: The potential number of various products that can be produced in a product family can lie in the thousands or even in the millions. Production starts with raw materials or various components, but with an identical process. Variability of the process is achieved by CNC machines or by the workers themselves. Representation of the product structure requires a generic structure in order to overcome data redundancy problems and to reduce the administrative efforts for defining orders and maintaining the product structure. Product families with many variants are comparable to prêtà-porter in the fashion industry. Some examples are automobiles, elevators, appliances and machines with variable specifications, complex furniture, or insurance contracts.