Organisations often struggle to keep the promised due dates for a customers project. This gets tougher in a shared & muti-project environment. The resources try to pad-up the task estimates & this further jeopardizes the project deliverables.

This is where Critical Chain Project Management [CCPM] the Theory of Constraints way of managing the projects can help the organisations overcome the obstacles & be the first to the market.

Critical chain optimizing recognizes that the entire safety margin originally built into every project schedule might not be required and that all tasks, in theory, could be completed ahead of schedule. Keep in mind, though, that as long as the safety margins exist in individual tasks, the ability to shorten the overall project length is minimalized. Yet, if the safety margins are all removed and even one critical task exceeds its estimated length, the completion date for the entire project is jeopardized.

Scheduling Buffers

CCPM methodology places safety margins—buffers—in the project schedule while pushing individual tasks to completion in the shortest time possible. The project manager applies and monitors four specific buffers that allow for contingencies where resource risks have the greatest impact on a project:

The project buffer protects the project from missing its scheduled end date due to variations along the critical chain. It places a portion of the safety margin time that was removed from each task estimate into a buffer task, this ensures that the entire project is protected instead of individual tasks. The project buffer is inserted between the final scheduled task and the scheduled project end date. The critical chain starts at the beginning of the project and ends at the start of the project buffer, not at the end of the project. The “Critical Chain” is the chain of tasks having both structural & resource dependency.

The feeding buffer minimizes the risk that late completion of a non-critical chain task will affect the critical chain. The project manager inserts an amount of time at those points in the schedule where inputs from non-critical chain tasks merge with critical chain tasks. The result is very similar to a relay race where the speed of the race, in general, is able to be maintained by the overlap in runners at the hand-off point.

The resource buffer is an alert that is sent to critical resources to ensure that they have time to complete their current tasks and begin to prepare for the critical chain task so that work can begin on the latter task as soon as the former task is completed. This buffer can be implemented easily and provides immediate benefit with little or no cost.

The capacity buffer places on-call resources that are available to avoid schedule delays due to unforeseen issues into the budget.

The Project Manager monitors & analyses the project buffer & the completion of the tasks on the critical chain. The project completion is directly proportional to the completion of the tasks on the critical chain

CCPM Process

In a nut shell, the CCPM process for developing and controlling a project schedule is composed of the following steps:

1.   Reduce individual task estimates to remove safety buffers. This is done either by slashing the estimate by 50 percent or by Sq. root of the sum of the individual tasks.

2.   Resource level the project to remove resource contentions. At this point, the critical path is transformed into the critical chain.

3.   Place these reduced durations into a project buffer, and insert this buffer at the end of the project.

4.   Insert feeding buffers at points where non-critical chain paths intersect the critical chain. It is important to monitor the feeding buffers as non-critical chain tasks may turn out to be critical chain tasks.

5.   Insert resource buffers where appropriate to reduce the probability that a critical resource is unavailable when scheduled.

6.   Insert capacity buffers where appropriate.

7.   Avoid bad multitasking.

8.   Schedule tasks to start late & finish early.

9.   Encourage tasks to be completed as quickly as possible. Emphasize the importance of start times and aggressive task completion rather than due dates.

10.                Manage buffers to support preventive and corrective actions.

Multi-Project Environment

CCPM can also be applied to a multi-project environment. The most loaded resource shared across projects, also called the drum resource, affects the overall completion date or schedule of the individual projects because each project is forced to progress at the pace of the drum resource.

Consequently, the critical chain and the paths that merge with it may result from resource dependencies outside the scope of a single project. Providing visibility to resource conflicts that exist outside the individual project is necessary to get a true picture of the overall project management environment within any organization.

Conclusion

If your organisation is failing on due dates, there is a resource conflict, lots of reworks, has a large number of projects requiring a few critical resources or a drum resource, then CCPM can be a driver in your organisational growth bringing in growth both in terms of organic & inorganic.