Constraints Analysis and task dependency are the core of effective Production Scheduling. Any task is simply an item of work with a specified duration, for which a single person is responsible. Unlike a relationship that just represents timing (typically using lags in conventional scheduling systems), within SPS|PM, the dependency between two tasks represents constraint i.e., work on the successor task cannot begin before all work on the predecessor task(s) has been completed. The dependent task is known as a successor, while the “providing” task is a predecessor or constraint.
Inserting a constraint adds a direct predecessor to any existing Milestone / Task. To insert a constraint task, complete the steps below.
Locate the Milestone / Task you wish to constrain in the Lookahead: Task List by selecting the Insert Task (Predecessor) Constraint icon for the task on the rights side of the screen as shown below.
Or
Select the Milestone / Task you wish to constrain in the Lookahead: Task List view by clicking once anywhere on task row. Once selected, the task row will highlight with a blue border, then select the Insert Task (Predecessor) Constraint icon for the task on the bottom toolbar as shown below.
Continue creating the constraint by following Step 3 in Inserting a New Milestone. By default, the Forecast Start will be set to ‘Calculate Forecast Start based on Predecessor’s Forecast Finish (“Continuous” Workflow)’ as shown below. See Forecast Dates in the Task Dates section for information on Forecast Start.
When finished entering the new constraint task attributes, click the Submit button as shown in the above image and the constraint task will appear in the Lookahead: Task List view.