The PRODUCTION kanban, again not surprisingly, is used to trigger the start of production of a batch of components. The kanban would contain details of the component to be produced, a description of the process, details of any materials required (which might have their own MOVE kanban) and the location to which the components should be sent when finished.
Any batch of components should be accompanied by a kanban at all times. A batch of parts waiting in inventory would have the PRODUCTION kanban from their production run. When the MOVE kanban arrives to trigger their release to the next part of the process, it replaces the PRODUCTION kanban in the container and the PRODUCTION kanban goes back to the preceding workstation to trigger production of the next batch.
Kanban control is a very simple process of which the key elements are:
- no movement or production can be started without the appropriate kanban (so a pallet of parts cannot be moved until the kanban arrives from the requesting workstation)
- movement or production is always triggered by the succeeding part of the process (they ‘pull’ goods towards them when they need them)
- all containers of the same kind of parts will have exactly the same number of parts
In true JIT and ‘lean’ style, there is also another imperative … over time there should be investigations undertaken to reduce the number of kanbans (i.e. to reduce inventory) and to reduce the time between kanban calls (by speeding up activity at workstations).