A constraint is a restriction on the output of a system. The constraint acts as a throttle, essentially establishing an upper limit on the amount of output that can be created. A constraint can be circumvented by designing a process or system to work around it, or by outsourcing work to another entity that is not subject to the same constraint. The output from a constrained system can be maximized by ensuring that the constrained resource operates as close to 100% of its capacity as possible. Examples of constraints are:
A production workstation that is operating at the top of its rated capacity
A selling process in which the sales demonstration team is already performing the maximum number of demonstrations per day
A constraint is also known as a bottleneck.