TOCC Project Game: does task duration variability “average out?”

Games can be an effective vehicle for testing and illustrating concepts. By building representative assumptions into a simplified model the impact of individual factors can be tested and evaluated.

One of the fundamental realities in managing projects is uncertainty. It can take different forms in reality (work content may change, scope can vary, tasks may be longer—or shorter—than expected, or resources might not be available when needed), but it is a fact in most projects. The project plan in the exercise below contains three simple assumptions:

1. Task dependencies (some must be done prior to others)

2. Task duration variability (there is an average time, which in reality may be longer or shorter)

3. Resources work multiple tasks (some resources need to perform more than one task on the same project)

The game will test the impact variability (both task duration and resource dependency) has on the overall project delivery.

Game Description

Below is a simple PERT chart of a project. Each task is done by a resource identified by color. Each will on average take 7 days to complete. The task dependencies are represented in the layout of the chart: Task 1 must be completed before Task 3 can begin, Task 2 must be completed before Task 4 can begin, and both Task 3 and Task 4 must be done prior to starting Task 5. There is only one resource of each color type so a task cannot begin until the resource is available (e.g. Task 1 and Task 3 cannot be in-process at the same time because they need the same resource, blue).

To play the game, roll two dice to determine the actual duration of each task (the average roll—task duration—is 7, but the actual can be anywhere between 2 and 12). Fill in the durations on a scorecard like the one below, until all five tasks are complete.

Example: the first roll is a 6, second roll (task 2) is a 9, third roll (task 3) is 4…  Note that Task 3, though sequentially after Task 1, cannot start until the red resource is finished with Task 2 and available.

Try it a couple of times to get a statistical sample of results, each iteration should take only a few minutes. When you complete the game click here to see a discussion of the outcome and some conclusions we can apply back to reality.