- Year not given
Just in time (JIT)
Short answer
A production and inventory philosophy that produces and delivers only when needed, in the quantity needed, to reduce waste. It uses a pull system, minimal inventory, and quality at source. Risks include supplier dependence and little buffer against demand changes.
What do you mean by JIT?
Just-in-time (JIT) is a production and inventory management philosophy, originating at Toyota (Taiichi Ohno), in which materials, parts and products are produced and delivered only when needed, in the quantity needed. The aim is to reduce inventory, waste and cost while improving quality and flow.
Principles
- Produce only what is needed, when needed ("pull" system, not "push").
- Keep inventory minimal; stock is a waste that hides problems.
- Small lot sizes and short set-up times.
- Quality at source: defects must be fixed immediately.
- Close cooperation with suppliers (frequent small deliveries).
- Flexible workers and equipment.
- Continuous improvement.
Kanban (signal card)
A Kanban card signals that a downstream process needs more parts from the upstream process.
Supplier -> [Stock] <-signal- Production -> Customer
pull driven by demand
Benefits
- Lower holding cost and less storage space.
- Reduced waste, scrap and rework.
- Faster response to demand change.
- Improved quality and productivity.
- Better cash flow.
Risks
- Dependent on reliable suppliers; delays stop production.
- Little buffer against sudden demand rise.
- Needs precise planning and discipline.
| Traditional (Just-in-case) | JIT |
|---|---|
| Large stock | Minimal stock |
| Push system | Pull system |
| Large batches | Small batches |
| Inspect for defects | Prevent defects |
In projects and IT
- Procurement of equipment only when needed in the schedule.
- Agile and lean software: develop features just in time based on priority, avoid over-planning and unused features.
Example: An IT firm ordering laptops for a new team only when the contract is signed avoids idle inventory and obsolescence.
✓ Answer checked by Claude Opus 5.5 (high effort)
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