The 9 rules of Theory of Constraint
To fully utilize the bottlenecks and what to produce, when necessary, the constraints of the theory is based on 9 rules .
Balance flow, not capacity
It is impossible, even adapting to balance the capacity of a company. So, we must regulate the flow in order to have a fluid flow. For this, the entire stream is to be mounted on one of the bottleneck.
An hour lost at a bottleneck is an hour lost for the total system
By definition, the bottleneck with no reserve capacity, it can not catch up. In return, extract additional capacity on the bottleneck will benefit the entire system.
An hour saved at a non-bottleneck is just a mirage
The resources remain dependent on bottleneck. An hour earned on a non bottleneck, does not benefit the system, but will benefit only stock that will increase.
The level of utilization of a non-bottleneck is determined not by its own potential but by some other constraint in the system
By applying the principle of the DBR, non bottlenecks resources must be keyed onto the bottleneck. Using non-bottlenecks according to their capacity, would only produce excessive stocks.
Utilization and activation of a resource are not the same
A resource must be enabled to use 100% but at the needs of the bottleneck.
Bottlenecks govern both the throughput and inventory in the system
The overall throughput of the system can not exceed the amount of the constraint. The blind activation of upstream resources can quickly inflate inventories.
The transfer batch may not and often should not be equal to the process batch
A transfer batch lower then a process batch allows to bind the parallel production of many resources, but also to forward the package more quickly to the next resource and therefore accelerate the flow.
The process batch should be variable, not fixed
Size Stationary batches impair the flexibility and responsiveness. The production were rarely regular (seasonal), variation in batch sizes is interesting to better monitor demand.
Capacity and priority should be considered simultaneously, not sequentially
The planning and scheduling are based exclusively on the bottleneck. It must always work. We must therefore ensure that capacity but also rawmaterial availability are consistent on the upstream positions.