The Theory of Constraints

The Theory of Constraints was developed by Dr Goldratt in his book:TheGoal and several others. The starting point is very simple and obvious: A chain is as strong as its weakest link. If you want to strengthen the chain, work on the weakest link

In systems terms: Any system's throughput is constrained by one bottleneck (or "constraint"). If you want to optimize the system, work on the bottleneck.

From this simple starting point several tools have been developed:

  • The "focusing steps" to optimize systems. Optimizing a system is never done, thus this is a "process of ongoing improvement".
  • The "Thinking Processes" for structured systems thinking (book:ThinkingForAChange)
  • "Throughput accounting" for measurement and feedback (book:ThroughputAccounting)
  • "Critical Chain" for planning (book:CriticalChain)
From that simple statement we can derive some unexpected consequences:

  • If you improve a non-bottleneck you will often worsen the performance of the system
  • The bottleneck should work at 100% capacity. The other part(icipants) of the system may not work at full capacity to get the best performance from the system.
  • When you design a system, you should choose carefully where to place the bottleneck.