A constraint is a time-based limitation used to describe when work can or should occur.
An activity in Flow Generative Scheduling is a task, milestone, or summary, such as a shot, asset, or sequence.
All activities in Flow Generative Scheduling can have constraints.
To easily apply a constraint:
When the Generate button is selected, the newly set constraints will be taken into consideration in the newly output schedule.
Constraints can be used to enforce that work must:
The types of available constraints depend on the type of activity, and what other constraints have been applied to the same activity.
Let's take a look at an example.
Lowlands is a film project with sequences and shots. DRV is a sequence, and DRV_0002 is a shot.
To complete the shot DRV_0002, 10 different tasks need to be accomplished, including matchmove, layout, animation, and lighting.
So far, no constraints have been applied to this schedule. Any one of the tasks within DRV_0002 can have any constraint applied.
Going up one level, constraints can also be applied to the shot. Constraints applied to this shot will be applied to everything in the shot’s hierarchy, which in this case is the 10 displayed tasks.
While the individual tasks have 8 available constraints that can be applied, the shot only has 4.
Going up two more levels through the sequence to the project-level, only 2 possible constraints are available for the project as whole.
While tasks, milestones, and summaries can all have constraints, not all types of constraints are relevant to each type of activity. Some constraints can contradict others. Constraints may not be available if an activity already has contradictory constraints applied.
For example, we can set a constraint on the DRV sequence.
We can choose to add a constraint to start no earlier than November 4. If we want to add an additional constraint, the only option will be to finish no later than a certain date.
Select the garbage can icon to the right of the constraint to remove it from the activity.
The + Add a constraint button will be greyed out when no further constraints can be applied to the activity.
Instead of setting the start and finish constraints, I can choose As soon as possible.
Once this constraint is applied, no further constraints will be available.
The As soon as possible constraint is an example of an exclusive constraint. Exclusive constraints cannot be combined with other constraints. See the chart below for more details on which constraints are exclusive.
When a constraint has been applied to an activity, it will be visible in the activity list in the Schedule tab under Constraints.
It's possible to apply infeasible constraints. An infeasible constraint means that the constraint applied to that activity is not possible to do.
When you try to apply an infeasible constraint, the constraint will appear red.
In the example below, I have a matchmove task selected and want to set it to finish no later than November 15.
As you add more constraints to a schedule, some can become infeasible to enforce. The Filter menu makes it easy to locate activities with this type of constraints.
To find activities with infeasible constraints:
The Gantt chart will update to display only the activities with infeasible constraints. Infeasible constraints will appear red. The activity list will display a warning next to the activity with infeasible constraints.
Locked activities happen when a schedule is imported with activities that start in the past. Any activities that are done will be locked and won't be editable. An example of this is an asset containing tasks that were already completed in the past.
A locked activity will display with diagonal lines on the Gantt chart.
Partially locked activities occur when a schedule is imported with activities that start in the past, and some of the activities in the same hierarchy are completed, while others are not.
An example of this is an asset containing some tasks that are already completed, and other tasks that have not been started and still need to be scheduled.
In the example above, one art and one modeling task have been completed on the PROP_IceCreamCone asset, while one modeling, and two texturing tasks still need to be scheduled.
A lock icon appears in the activity list next to the completed tasks.
An activity can be partially locked and have infeasible constraints applied. In these scenarios, the Gantt chart will display in red and with diagonal lines.
