Critical chain - Explanation and definition of critical chain

What is the critical chain

Critical chain is a methodology developed in the 90s focused on improving Project management (administration and programming). The use of the critical chain has reduced the overall execution time of projects and the cost of it.

Critical chain is also known as CCPM stands for Critical Chain Project Management, this methodology was introduced in 1997 by Eliyahu M. Goldratt in his book "Critical Chain" which reached a success in sales and creating a market of consulting and implementation of this methodology in different companies and organizations worldwide.

Unlike other management techniques and project scheduling as GANTT, PERT, CPM, project management through critical chain is based on the management of buffers which are generated by the elimination of tolerance and protection times we attach to a task, on the other hand the critical chain tackles the problem of limited resources in multiproject scenario.

The critical chain method identifies a number of times of protection and / or tolerances assigned to a task which are induced by human behavior, such times are based on two theories:

• Student syndrome - All homework is always done at the last moment.

• Parkinson's Law - Any task expands over time until it fill the time available.

The calculation of such protection times and / or tolerances directly affect the calculation of the buffers.

Depending on the type of project management (monoproyecto or multiproject) the critical chain defines the following buffers or dampers:

• Draft buffer

• Resources buffer

• Supply buffer

• Capacity buffer

• DRUM buffer

Critical chain methodology

Here are the steps for the implementation of the methodology defined critical path:

• Generation of the flow project, identifying the tasks and their relationships and resources.

• Identification of the critical chain

• Identification and elimination of the tolerances of the tasks belonging to the critical chain.

• Calculation and identification of buffers depending on the tolerances identified above

• Location of buffers in the critical chain

• Management of buffers

Once we built our critical chain project management will focus on the management of this buffers, this requires the generation of reports on the situation of the project and its buffers in order to take appropriate actions in case. Reports of critical chain usually define a series of indicators such as the progress of the critical chain, the percentage of consumption of buffers, etc. That will be monitored...

Today there is specific software (PS8, Prochain, CC-press ...) that allow you to calculate and generate all the elements of the critical chain, on the other hand this type of software automatically generates the necessary reports to manage Project buffers.

Companies of software development , manufacturers of surgical materials, construction of public works and a host of different companies and organizations have successfully implemented the critical chain methodology as a basis for the management of the projects carried out.