Layouts

Facility layouts come in three basic flavors.

1. Unplanned Layouts. Some facilities are not arranged by any master plan. As new machines are needed, they are placed where they will fit. It is fairly uncommon for this method to be used throughout an organization, but many will have a few machines that are obviously placed where there was space.
2. Functional Layouts / Process-Oriented Layouts. This layout style is characterized by groupings of similar processes that serve multiple product lines. For example, there may be a welding cell, a stamping cell, and a machining shop. It is the traditional way facilities are organized.
3. Product-Oriented Layouts. In this layout, machines and work areas are positioned sequentially based on the steps required to build a particular product. The closer the machines are, the easier it is to implement flow. This layout often utilizes small, right-sized machines instead of large multi-purpose systems.

The third variation is the preferred method in Lean. It eliminates a great deal of coordination, which adds complexity and waste. It also lowers the need for transportation, which tends to increase batch sizes.

As with most things, though, there is a tradeoff. When there is a large mix of low volume products, it is too costly to create small, single-product work cells. Functional work areas with kanban systems and/or supermarkets are a reasonable alternative in these cases.