Definition
The idea of rejecting bulk processing: products move between processes in a minimum increment (extremely single), with back-track pulls as needed, and only qualified goods can flow into the next process.
In detail
Flow production (one-piece flow) is a production philosophy that emphasizes products flowing continuously between processes in minimal batches (ideally one piece), pulled by downstream processes as needed, with only good quality products flowing to the next process. It aims to eliminate waiting, handling, and excess inventory in batch production, shorten lead times, and improve quality. Compared to batch production, one-piece flow quickly exposes problems but requires stable processes and quick changeover support. The output is typically a continuous flow production cell, operating with standard work and a pull system.
Example in practice
A machining factory changed from batch processing to one-piece flow. Equipment was arranged in a U-shape layout, and operators were multi-skilled. When the downstream process needs a part, the upstream process produces one and immediately transfers it. As a result, work-in-process inventory was greatly reduced, quality issues were detected promptly, and delivery lead time shortened from one week to one day.