How do Task Types work with Monte Carlo
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How do Task Types work with Monte Carlo
What is the difference between Fixed Units, Fixed Duration, and Fix Work. How does it affect probabilistic calculations?
Jason

 Posts: 897
 Joined: Wed Nov 09, 2005 9:55 am
Re: How do Task Types work with Monte Carlo
Task types are set in the Task Information > Advanced tab.
To understand how Task types work it is useful to think of a 3sided triangle in which the sum of the lengths of the sides always have to add up to fixed value eg. 100. With the added condition, that if you fix the the length of one side (A), then if you modify the length of another (B), then C will have to change in response. So if A= 40, B=30, and C+30. If we make A fixed and change B=40, the C would have to change to 20.
With task it means that if we fix units (the % of resource that will be applied to the task) then if we change the task duration, the amount of work will adjust accordingly. as well. For example if we had a task with Fixed Units, that 1 resource at 50% units, 40 hours duration would generate 20 hours of Work. If the task duration in increased to 80 hours, the amount of work would increase to 40 hours. Fixed Units is generally the default Task Type as this the most intuitive process for most schedulers.
However if we took the same task and and set it to Fixed Work. This is a useful setting if you understand the amount of work, and what could vary is either the amount of time focused time that a resource is on the activity or the number of calendar days that the resource is available. In this case, if you changed the duration to 20 hours, Work would remain at 20 hours and the units would be recalculated to 100%.
The same holds true for fixed duration, if you change the Units, Work will be recalculated and visa versa.
For simulations, the Task types work in the same manner. But it takes into account the range of the uncertainty defined by the Low and High estimates for the task. So for each iteration take a random value defined by the statistical distribution and calculate the duration, resources, or units based on the random value.
To understand how Task types work it is useful to think of a 3sided triangle in which the sum of the lengths of the sides always have to add up to fixed value eg. 100. With the added condition, that if you fix the the length of one side (A), then if you modify the length of another (B), then C will have to change in response. So if A= 40, B=30, and C+30. If we make A fixed and change B=40, the C would have to change to 20.
With task it means that if we fix units (the % of resource that will be applied to the task) then if we change the task duration, the amount of work will adjust accordingly. as well. For example if we had a task with Fixed Units, that 1 resource at 50% units, 40 hours duration would generate 20 hours of Work. If the task duration in increased to 80 hours, the amount of work would increase to 40 hours. Fixed Units is generally the default Task Type as this the most intuitive process for most schedulers.
However if we took the same task and and set it to Fixed Work. This is a useful setting if you understand the amount of work, and what could vary is either the amount of time focused time that a resource is on the activity or the number of calendar days that the resource is available. In this case, if you changed the duration to 20 hours, Work would remain at 20 hours and the units would be recalculated to 100%.
The same holds true for fixed duration, if you change the Units, Work will be recalculated and visa versa.
For simulations, the Task types work in the same manner. But it takes into account the range of the uncertainty defined by the Low and High estimates for the task. So for each iteration take a random value defined by the statistical distribution and calculate the duration, resources, or units based on the random value.
Intaver Support Team
Intaver Institute Inc.
Home of Project Risk Management and Project Risk Analysis software RiskyProject
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Intaver Institute Inc.
Home of Project Risk Management and Project Risk Analysis software RiskyProject
www.intaver.com