Constraints are limitations that you set on tasks. For example, you
can specify that a task must start on a particular date or finish no
later than a particular date. In RiskyProject, you can assign one of
four constraints to a task:
• As Soon As Possible (default)
• Start Not Early Than
• Must Start On
• Must Finish On
Use the General tab of Task Information dialog box to add or modify
constraints. If you set a constraint to Start Not Early Than, an
additional edit box opens in which you set the date for this
If you assign a constraint other than As Soon As Possible, the
background color for low, base, and high Start Times or low, base
and high Finish Times changes to orange and the icon next to the
task name has a red dot added to indicate that the constraint is
other than As Soon As Possible.
Use constraints to ensure that that task starts or finishes on the
specific dates. Use caution when you link tasks with a constrained
start or finish time with predecessors because of the potential for
scheduling conflicts. In this situation, to avoid scheduling
conflicts, set the constraint to As Soon As Possible.
Constraints affect both probabilistic and deterministic
calculations. If you change the Low or High Start times, the
constraint is set to Must Start On, similar to when you change the
Base Start time.
task has a constraint other than As Soon as Possible, it may not
shift due to the nature of Monte Carlo calculations, even if
predecessors have risks and uncertainties. Therefore, use caution
when you planning to perform probabilistic calculation with
When you enter actual start date of the task as part of tracking
input, task would become constrained for the probabilistic
calculation only. Start time will not change regardless of risks and
uncertainties for predecessors.