Project management through the critical chain: a beginner's guide.
Do you want to improve the success rate of your projects? Do you want to finish your projects on time and reduce costs? Among the Many Project management methodologies Existing, the critical chain method (Critical Chain Project Management or CCPM in English) may be of interest to you.
Lack of focus and the inability to manage uncertainty are two major causes of project delays, poor quality, excessive deadlines, and lack of team spirit. The critical chain method addresses these main causes and thus makes it possible to improve the speed, quality, timeliness of projects as well as team morality.
Definition
The critical chain method comes from the Theory of Constraints (Theory of Constraints or TOC in English), developed by Eliyahu M. Goldratt in his book The Goal (The Goal) published in 1984. Constraint Theory is a methodology that allows you to identify the constraints (also called bottlenecks) that prevent you from reaching your goal and making them disappear. Eliyahu M. Goldratt adapts the method to project management with his book Critical chain, published in 1997.
The critical chain method is an alternative to Critical Path Method. Remember, the critical path represents the longest succession of dependent tasks that determine the duration of the project. However, this method is criticized for considering that resources are unlimited, which is rarely the case.
To remedy this, the critical chain refers to the longest sequence of dependent tasks taking into account the number and availability of resources through leveling. Levelling is an essential concept that consists in delaying the completion of a task until the resource allocated to its completion is available. In this way, resource conflicts are avoided, i.e. a resource called upon to perform several tasks at the same time.
In addition to leveling, this method also establishes the creation of safety margins (called Buffers), the concept of backplanning and management by duration and not by tasks.
How does it work?
Follow these 8 steps to apply the critical chain method to your projects.
1. Define tasks and resources
The start remains the same for all projects: start by identifying all the tasks to be performed, assess how long they will take to complete and define the resources (human and material) that you will need to complete your project.
2. Identify the critical path
Determine the critical path of the project, that is, the longest succession of tasks that depend on each other, considering that your resources are unlimited. Reverse schedule (starting from the end of the project) by scheduling tasks at the latest.
3. Reduce the duration of each task
In project management, the duration of each task is generally overestimated in order to anticipate possible delays and hazards. However, this is ineffective because of Parkinson's law (all work tends to be spread out to take up all the time allotted to it), the student syndrome (you get to work at the last moment) and multitasking.
So remove the safety margins and thus halve the duration of each task. The safety margins are kept in the form of stamps (Buffers) and placed at the end of the project in case of delay.
4. Identify and manage resource conflicts
To avoid that one of your collaborators ends up performing several tasks simultaneously, in other words multitasking, you must identify resource conflicts and level your resources by reorganizing your project. Be careful to always respect the dependencies of the tasks.
5. Identify the critical chain
Now, you can identify the critical chain, which is the longest succession of tasks that takes into account both the interdependence between tasks and between resources. This is the difference with the critical path, which does not take into account the availability of resources. The critical chain determines the duration of the project.
6. Insert stamps
Gold stamps Buffers Make it possible to protect the project from possible delays in completing tasks. The Project Stamp (gold) Buffer Project) is equivalent to half the duration of the project. It is placed at the end of the project.
The other buffers make it possible to absorb the delay in secondary tasks (which do not belong to the critical chain).
7. Set the countdown timers
The critical chain can be similar to a relay race where each task starts as soon as the one before it finishes. To ensure that each resource will be ready to devote themselves entirely to completing their critical task when the time comes, set alerts or countdowns one week before the start of each task in the critical chain to prevent the resource from starting their task.
The purpose of countdown timers is to avoid starting a task late as this could have a negative impact on the entire project.
8. Manage the project
Manage your project by monitoring the availability of your resources and by monitoring the consumption of buffers. If less than a third of the stamps are consumed, everything is fine. If more than a third party is used, assess risks and implement corrective actions. Beyond Two Thirds, a Crisis Unit Must Be Convened
Conclusion
The critical chain method is more realistic and more effective than the critical path method because it takes into account the availability of resources, thus avoiding multitasking and resource conflicts. Safety margins are shared at the end of the project, which makes it possible to reduce the average duration of projects. Finally, this method is ideal for multi-project management that requires a large amount of resources.
