RiskAMP.Task

RiskAMP Support Functions

This is a support function for building project planning models.

Sample should be the calculated value for this task, usually the output of a random distribution function. If the task is skipped in a given model or trial the value can be zero.

Dependencies are references to one or more RiskAMP.Task functions describing tasks that must be completed prior to this task. Enter multiple dependencies as separate arguments.

Example

Here’s an example of a simple project model:

In this example, we use the RiskAMP.Task function in column G. Each row uses it in a slightly different way.

In row 2, there are no dependencies for the first task. So it just returns the sample value.

In row 3, the task depends on the prior task. So there is one dependency. The result is essentially the sample value for row 3, plus the task value from row 2. That means that in this iteration of the model, we expect task two to complete at this point.

Rows 5 and 6 represent two sub-tasks. These can run simultaneously, so they don’t depend on each other. But both rows depend on the previous task (in row 3).

In row 8, we’re figuring out the time to complete this project. This entry has no sample value, because it’s just accounting. But it depends on both of the subtasks in rows 5 and 6, because we are waiting on the longer of those two parts.

How it works

The function itself is very simple — it essentially says “start when the last dependency is complete; then add the time to run this task”. It’s equivalent to writing (in Excel)

=MAX(Dependencies) + Sample

So why use a distinct function for this? One, it helps identify and clarify the specific use case. And two, it helps with our automated tooling.