Short answer

The Theory of Constraints focuses improvement on what currently limits the result of a system. Identify that constraint, use its existing time well, make the rest of the flow support it, add capacity if justified, then check where the limit moved. Follow good output or customer delivery. Keeping every machine busy can increase inventory without improving either.

Key takeaways

A clear priority for the whole flow

Less avoidable lost time at the constraint

Capacity spending checked against the actual limit

Define the result and its boundary

Choose the output the operation needs: good completions, customer deliveries or another clearly defined result. Keep demand and the time period beside it. A resource that is busy making unwanted stock is not helping that result.

Find what limits that result now

Compare capacity with the product mix, then observe queues, blocking and starvation. Starvation means a process waits for incoming work; blocking means it cannot pass work forward.

Check scheduling and release rules as well as equipment. The limiting condition can change when demand, routing or reliability changes.

Use and support the existing constraint

First reduce avoidable waiting at the constraint within approved working limits. Make material, information and qualified people available when needed. Then adjust other steps so they support its pace rather than flooding it.

  1. Identify

    Find the condition that currently limits the system result.

  2. Exploit

    Use the available constraint time effectively without bypassing safeguards.

  3. Subordinate

    Align release and supporting work with the constraint.

  4. Elevate

    Consider added capacity when the remaining limit justifies it.

  5. Repeat

    Find the new limit after the change.

Check the rule before buying equipment

A model or limited trial can help distinguish a capacity shortage from avoidable waiting. Compare the complete flow under the same demand assumptions.

Recheck after the improvement

Once a loss is removed, another step or policy may become the limit. Keep checking delivery, queues and operating cost. The old bottleneck should not remain the default priority after the evidence changes.

A related example from Abolfazl

Abolfazl connects release decisions, queues and launch lead time.

Read the companion note

In English, on founder Abolfazl’s personal blog. This is related reading, not an independent technical source.

Practical checklist

  • Define the system result and demand.
  • Use a consistent time period.
  • Check capacity for the actual product mix.
  • Observe blocking and starvation.
  • Look for policy and release limits.
  • Protect the constraint without creating excess WIP.
  • Test the case for extra capacity.
  • Find the new limit after changing the flow.

FAQ

FAQ

Sources and further reading

Authoritative references used to research and verify this guide.