According to the definition of one piece flow or continuous flow in Lean Dictionary by Ray, an American lean research institute chaired by Womach, a lean master, it is: "To produce and move one (or a small batch or a fixed batch) workpiece at a time, so that the workpiece can go through a series of processing steps as continuously as possible, and each step is just completed when the next step is needed. Continuous flow can be realized in many ways, from moving assembly line to manual transfer of production unit. Continuous flow is also called a flow, one flow after another, leaving one after another, etc. "[1]. By definition, one piece flow includes several elements:

Produce and transfer one or a fixed small batch of parts (such as a box) at a time;

As continuous as possible.

The up-and-down process is just a connection.

Starting from the definition of "one stream", we have a clearer understanding of the demand of "one stream":

1 one piece flow emphasizes "flow" and single or small batch circulation, rather than the whole batch transfer, intermission and waiting. One piece flow is the highest level of lean value chain. In various lean organization methods, not all processes are connected by "supermarkets" in one piece flow.

2 one piece flow process is automatic (by workers) flow, there is no intermittent and manual control between processes, and the parts automatically rotate after entering the unit until they are completed or flow out of the unit;

When realizing one piece flow, it is the most basic condition to quickly process different kinds of parts on the same equipment. However, the proper connection between continuous processes and processes is a more essential feature of one piece flow.

One piece flow is not contradictory to container flow or small batch flow. In fact, in most enterprises that implement JIT production, the units pulled by Kanban are standard containers. Moreover, according to the product characteristics of the enterprise-small volume and large quantity, it is not convenient to transfer them one by one.

Five advantages of one piece flow: Yes

Simplify site planning and scheduling management,

Decentralize management decision-making power, improve the response speed of exceptional events, and give play to the creativity of employees.

Find quality defects in time to prevent the occurrence of unqualified products in batches.

Shorten the production lead time,

Reduce inventory and WIP costs,

Reduce the area occupied by the workplace.