This is quite a simple request.

I have a 150 line Gantt Chart showing project planning to FY end. Approx 30 of the lines are dependencies with Finish to Start attributes. I would like to run scenarios on the timelines similar to

A loss of 20% resource will have the following impact on timing

Doubling resource will have the following impact

If Dependency A is delayed by 2 months it will have X effect on the timing of the plan

Does any software allow one touch scenario modelling?

  • 1
    This question seems on the bubble. Is there a way to reword it so that it isn't a product-recommendation question?
    – Todd A. Jacobs
    Nov 11, 2014 at 10:45

2 Answers 2


This is a Monte Carlo Simulation exercise; however, you are approaching scenarios too simplistically, in my opinion. You are creating very simple if-then scenarios in which you can make a very simple but inaccurate calculations. For example, doubling your staff will decrease your duration in half, assuming a linear relationship between work, duration, and resources. You can make a similar calculation reducing your resources' utilization by 20%.

However, work is not this deterministic. In fact, you have hundreds of probabilistic variables banging up against each other with varying degrees of cause or correlation, INCLUDING aleatory variability. Using Monte Carlo simulation, you would load in the tool your assumed distributions for the variables at play, e.g., costs, resource utilization, time, etc. The tool will run thousands of simulations randomly choosing a a value within those distributions and produce a final result on whatever metric in which you are interested.

The resulting distribution, say on costs, is far more valuable to you for planning purposes and risk management then a simple calculation that says, reducing 20% in resources will cause x% increase in time. That is a deterministic result that has an extremely low probability in occurring.


Not sure about one-touch scenario modeling, but I know Microsoft's project does attempt to come up with a completion date, which would be impacted by a resource being 20% unavailable. The 2mo part could be done too, as each resource has a calendar, but it may be a little bit of a pain.

I am actually currently working on a feature just like this for my own product. I represent resources with profile pages. Each resource profile page has their availability per project and working dates. It is not designed for this one-touch-change-and-see modeling, but with few touches it one could use it to simulate scenarios. Would that work for you?

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