A Product Family Matrix can be used to group products into families. To use the matrix, indicate which process steps are used by each product. Then, look for groupings of common process steps. The groupings are the product families.
The process steps are arranged by flow order with downstream processes last. Downstream steps are those process steps that are closer to the customer. Many times, the major difference between product families is the use of downstream process steps.
With product families, workflow layouts can be configured to accommodate small differences in the workflow by building in detours and planning for the use of portable equipment.
Product families do not have to serve the same market. Think in terms of shared processes, not shared markets.