Recognizing Constraints & Bottlenecks

Posted by psabilla

November 13, 2006

All dynamic systems — online or offline — consists of discrete and dependent processes. Each step in the system has a finite capacity. When one step is feeding more than what the next step can handle, you’ll have yourself a constraint. Constraints or Bottlenecks aren’t bad, they’re expected and are found in any process. The key is recognizing and then managing the constraint.

Recognizing Your Constraints

Imagine the following generic process:

www.shmula.com, theory of constraints

It doesn’t even matter what IPH stands for — just look at the raw outputs, because that is what will “feed” the next dependent process step. Do you see the constraint?

The Role of a Bottleneck

Bottlenecks determines the throughput of a system.
An increase in the bottleneck rates is the only way to increase throughput.
All other process steps should be slaves to the bottleneck.
It’s okay to take resources from a non-bottleneck if it will help the bottleneck.

Managing Constraints & Bottleneck Principles

Bottlenecks should never be idle; to lose time on a bottleneck, is to lose throughput.
Never let a bottleneck run out of work. It’s okay to build inventory in front of a bottleneck.
Increase productivity rates (offline and online processes) by reducing down-time, change-over time, and off-task time.
Reduce defects by having Quality Assurance and Quality Control in front of a bottleneck, not after.
Focus all improvements on the bottleneck.

In any offline or online process, there will be contraints. It’s important that you identify the contstraint, then manage it; once you manage it, it’s important to remember that bottlenecks move. When this happens, follow the above steps again to identify, then manage your bottlenecks.

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For an application of The Theory of Constraints, please see the following articles: