Manufacturing Operations · Production flow · Component
The flow map
How work moves through production, with queues and handovers made visible rather than drawn as arrows.
The deliverable
What it is
Flow maps drawn as a sequence of operations hide the queues between them, which is where most of the time goes.
Batch size belongs on the map, because a large batch means nothing moves downstream until the whole batch is finished.
One level in
What it is made of
Each element is a constituent part of the component. Follow one to see the attributes it carries.
The operations
Each production step with its cycle time and batch size.
3 attributes: Operation · Cycle time · Batch size
LearnThe queues
Where work waits between operations, and how much waits there.
3 attributes: Queue size · Queue time · Before operation
LearnThe rework loops
Where work goes backwards, and how often.
3 attributes: From and to · Loop rate · Added time
Learn
Queue size is directly observable by walking the floor, and it is the most commonly omitted number on a flow map.
The other components in production flow
The WIP limit
How much work is allowed in the system at once — the counter-intuitive lever that shortens lead time without reducing throughput.
LearnThe flow measure
Working time against elapsed time, per product line — the number that shows how much of the lead time is actually production.
Learn