Product Family

For the purposes of continuous improvement, a product family is a group of products that follows a similar series of process steps. The value in this type of organization is that it supports flow. Similar products can be combined onto a mixed model production line. Generally speaking, the higher the pace of production, the more magnified the impact of each improvement will be. All things being equal, kaizen activity on a higher volume production line will generally yield better bang for the buck than improvements made on a low volume line.

Note that product families from the marketing standpoint and from the production standpoint may be slightly different. In marketing, product families tend to be organized around function or customer. For the production standpoint, the key driver for product family is process.

Remember, one of the keys to Lean is to create flow. This is easier to do on a production line where there is a high volume with low variation. It becomes more difficult when the pace is slower and there are numerous differences between products.

Product families are a way to strike a good balance. They put similar products into one production line to conserve improvement resources. Imagine you have 10 products that you produce. One option is to have 10 production lines. If there is a high enough demand to support 10 lines, you’ve got a great situation. For many organizations, though, individual products are not produced at that volume.

Product families allow you to make two or three or four production lines for those 10 products. The downside, of course, is that mixed-model production lines have to be flexible. Flexibility typically has a cost in productivity, space, or equipment. By carefully choosing which products travel down the same line, you can minimize those costs.

You may have to get creative in how you set up your product families in different areas. It can get confusing if you have a product that has different logical groupings in different areas of the factory.

Consider if you have a facility that makes small motorized hobby vehicles. You might produce both go-karts and snowmobiles and have a variety of electric and gas power options for both vehicles. You may organize your motor production area by electrical and gas product families and your assembly area by go-kart and snowmobile.

Look at each production area separately. The Parts Quantity/Process Routing (or PQ/PR) chart is the tool of choice for selecting product families.