Pull System vs Kanban vs CONWIP: The Production Control Trade-offs

Key takeaways

• Pull system = downstream demand pulls work; upstream produces only on signal.
• Kanban = card-based pull, WIP capped at each step.
• CONWIP = total WIP cap across the whole line.
• Kanban produces more even workload; CONWIP produces higher throughput at higher variance.

Short answer: Pull means downstream pulls from upstream. Kanban caps WIP at each step. CONWIP caps total WIP across the whole line. Kanban gives smoother flow; CONWIP gives higher throughput. The choice depends on whether even workload or maximum output matters more. See also Kanban Cards vs Electronic Kanban.

Pull system fundamentals

Production is signaled by downstream consumption, not pushed by upstream schedule. Reduces overproduction, the worst of the seven wastes.

Kanban specifics

• Cards represent permitted work.
• Each step has a card limit.
• Card returns trigger upstream production.

CONWIP specifics

• Total WIP cap, not per-step.
• When output exits the line, new input enters.
• Bottleneck balances naturally.

Trade-offs

• Kanban: smoother flow, lower variance, slightly lower throughput.
• CONWIP: higher throughput at the bottleneck, higher WIP variance upstream.

When kanban fits

• Stable demand.
• Multiple product types with separate kanban loops.
• Operator workload smoothness matters.

When CONWIP fits

• Variable demand.
• Bottleneck-dominated lines.
• Throughput priority.

Common mistakes

1. Calling MRP "pull." MRP is push.

2. Kanban without sized buffers. Stockouts or overproduction result.

3. CONWIP without bottleneck identification. System floods upstream of bottleneck.

4. No review. WIP caps stay stale as demand changes.

How OEE relates

Pull systems affect OEE Performance (smoother flow, less micro-stoppage) and Availability (less starvation at bottleneck).

How a modern OEE platform supports both

Fabrico's OEE module visualizes WIP and queue at each station and supports kanban/CONWIP-style monitoring.

See how Fabrico captures this automatically — explore OEE for manufacturing or book a demo.

Related reading

• Kanban Cards vs Electronic Kanban
• Kaizen vs Kanban
• Andon System Design

Frequently asked questions

Is CONWIP a kanban variant?

Yes; both are pull.

Can I mix?

Yes; hybrid systems are common.

Which gives higher throughput?

CONWIP usually.

Which smooths workload?

Kanban.