Critical Chain (CC)

In spite of tremendous development in the field of project management software tools and often huge investment in the training of project managers, the results of the classical project management remain far behind the expectations. While Agile methodologies are gaining popularity in some areas of project environment, the usual problem of projects behind schedule and/or over-budget hasn’t been solved in most organizations.

Why is that?

Many various SW applications as well as seemingly new systems have been developed, but in fact they all are based on the basic project management principle known as the Critical Path.
The Critical Path methodology is historically associated with the development of new line of American submarines in the 50’s. The methodology was very successfully used here for the first time. The above mentioned project however differed slightly from all other projects – it was financed by a practically unlimited budget approved by the United States Congress.
If we want to be equally successful with the Critical Path in project management today, we ought to ensure the same types of resources. This however doesn’t seem to be feasible under the usual everyday market conditions.

Does any other possibility of managing projects exist?
-Yes. It’s called Critical Chain!

 A standard application of the Critical Chain methodology reduces project cycle times by circa 30 %, without any need for additional resources, achieving a significant increase in OTIFOB project completion. (due date performance reliability.)

Which areas are being solved by the Critical Chain?


1.    Multitasking

Multitasking is a concomitant of the matrix organizational structure or more projects carried out simultaneously. It means identical workers involved either in more simultaneously running projects or carrying out other tasks due to their regular work engagement. Task priorities in this situation are formed mostly by the pressure of project or line managers.
In practise multitasking is manifested by permanent alternating between tasks.
Multitasking prolongs the project duration 4 – 6 times.

2.    The project duration depends not only on the Critical Path but also on resource availability.

• Critical Chain is defined not only by the longest sequence of dependent activities, but also by the availability of the necessary resources in given time frame.

3.    Murphy’s law in project management: We can summarize it as „Anything that can go wrong, will go wrong“

Uncertainty in execution of project activities is separated from the individual activities and accumulated into project time buffers.
Instead of time reserves usually added to every project task, Critical Chain uses accumulated time buffers, placed at the end of the project and on project paths connecting to the Critical Chain of the project
The system of separated time reserves is based on the assumption that everything will go wrong, which is approximately equally probable as the assumption that nothing will go wrong. Accumulated time buffers enable utilization of positive variability in project execution.

4.    Parkinson’s law in project management: Time necessary for any task to be completed expands so as to fill the time dedicated for its completion

•    In conventional project management it’s very unthrifty to finish a task ahead of the set milestone. Why? Try to find the answer yourself.

5.    Student’s syndrome

•    The principle is equal to preparing for an exam. Resources tend to start on project task at the last moment. They have many objective reasons for this after all, which they cannot really influence anyway. Naturally the probability of the project being behind schedule increases dramatically by this.

6.    The Relay Runner principle

•    Critical Chain by means of project management tools creates a situation, where individual resources having started on a project task „run as fast as possible“ and hand it over as soon as it’s finished regardless of any milestone.

7.    Monitoring the execution of tasks based on time left in time buffers instead of milestones

•    Critical Chain limits milestones as much as possible (leaving usually only the contractual ones). The project delivery date is protected by means of accumulated time buffers used simultaneously for prioritization.

8.    Project management based on time buffers consumption

•    The real time management of the project flow is carried out by means of integrated messages on task status and buffer consumption. Task priorities are also assigned and emergency plans created in accordance with this.

In general it is possible to say that Critical Chain on one hand significantly cuts project lead times while on the other hand substantially increasing the probability of on time, without compromising the specifications and on budget completion of all projects. CC is able to achieve this in case of individual projects as well as (and especially) in multiproject environment.
Completed implementations prove that organizations, who applied Critical Chain, are able to manage up to 50 % more projects with greater certainty and in a calmer atmosphere.