1. The seven wastes (muda), with factory examples
- Overproduction: making tables before anyone has ordered them.
- Waiting: assemblers standing idle while parts are still being cut.
- Transport: moving timber back and forth between distant parts of the site.
- Over-processing: polishing surfaces that customers never see.
- Inventory: stacks of finished stock that tie up cash and space and may go out of style.
- Motion: workers walking to fetch tools that could be kept at each station.
- Defects: pieces that have to be reworked or scrapped.
2. How JIT and kanban help
In a pull system, production only starts when an order or a downstream process asks for it. A kanban card or signal tells the previous stage to make more, which stops overproduction and cuts inventory.
3. The resilience trade-off
Holding very little stock saves money, but it leaves no buffer if a supplier fails, as many firms found during the pandemic and recent shipping disruptions. A balanced recommendation keeps JIT for most parts but holds safety stock of critical items and uses more than one supplier for them.