A constraint "predefines the start, finish, or both dates of an activity."
|“||[f]actors that impose restrictions and limitations on the system. Actual limitations associated with the use of the system.||”|
"Constraints may result as the consequences of existing agreements, management decisions, technical decisions, technology limitations, or the [[operational environment]. . . . Constraints are generally associated with characteristics of the environment specific to the various domains associated with the system."