Assembly & Integrated Workcells

But there is another method for providing smooth demand: Final Assembly Cells. In this approach, the assembly line is broken down into multiple, smaller workcells. Each workcell produces a single model or, perhaps, several models with a high degree of part commonality.

Toyota probably used Mixed Model Assembly lines because their large Detroit-style lines were already in place. It may have seemed like a natural and easy solution to the problem of upstream demand smoothing.

A further evolution of mixed model assembly cells is to incorporate some (or all) upstream fabrication into the cells. The figure below shows how the fabrication equipment for each model joins with respective assembly operations in a cell or sub-cell. It provides even closer coordination and  corresponding improvements in quality and inventory.