Any limitation imposed by the market, customers, regulatory, or other group.
Any policy, machine, person, or activity that prevents a system from meeting or exceeding the external demand.
Constraints that affect the system only through the interaction with the primary constraint; these are periodic constraints that affect the system for brief time periods only.
A constraint that truly limits the system performance.
1. Identify the systems constraints. 2. Decide how to exploit the constraints. 3. Subordinate everything else to the constraints. 4. Elevate the constraints. 5. If a constraint has been-broken, repeat steps 1 through 4.