Critical Chain Success Tip - Plan for Uncertainty

In conventional project management there are two widespread beliefs that are challenged by Critical Chain Methodologies:

1. Safety time embedded with individual tasks ensures timely completion of the project
2. Project plans with high levels of detail gives high degrees of control

Instead Critical Chain practitioners believe these widely held beliefs to be flawed and instead focus on the completion of projects rather than tasks and place significantly less importance on individual tasks and the level of detail they describe.

Safety is embedded in tasks to try and accommodate uncertainty; typically this is around 50% of any estimate of task duration. Even with such high levels of safety it is not unusual for late completion of projects, as often the degree of uncertainty in several key tasks is even higher than initially estimated.  In most cases the task embedded safety is much higher than required gets wasted, preventing the project from flowing.

If embedding safety inside tasks and placing these tasks in highly detailed project plans is not the solution to delivering projects on time what is?

Critical Chains focus is on increasing project flow which it does this by cutting task time estimates in half, removing the embedded safety within the tasks, and then adding half of this removed safety to the end of the project to act as safety for the project as a whole. This gives much higher potential for the project to flow.

However this in itself is not sufficient, to ensure good flow the project needs to be well managed. Experience shows us that projects with too many tasks (greater than 300) become unmanageable. So the second key principle of Critical Chain is to limit the number of tasks in the project, by reducing the level of detail in each task, this allows the project manager to ensure good flow is maintained.