For the ease of understanding, this author is using the word ‘piece’ to mean (in the generic sense) the making of a tangible product. It could be an ice cream cone, a widget, or an automobile. One of the tenets of Lean is single piece flow. Instead of building up a stack of inventory between the steps in the process, the idea with single piece flow (also known as one piece flow), is to build at the pulse rate of customer demand. This pulse rate of customer demand, known as takt time, ebbs and flows over time. With single piece flow, the idea is to make a piece only when the customer asks for one.

Use: Single piece flow obviously works well with a just-in-time methodology.  This is in contrast with batch processing. Many organizations believe batch processing is the most efficient way to produce. It flies in the face of common sense, but the truth is — batch processing usually isn’t efficient. In fact, it’s very inefficient and the worst of all, the customer usually has to wait until the next batches produced to get exactly what they want. The most efficient organizations strive to develop processes designed for one piece flow.

Six Sigma Terminology