GS, Critical Chain_Project Management

GOVERNMENT SOLUTIONS

	Project Management Services / Earned Value Management
	Comprehensive Project Management Services

Critical Chain

CRITICAL CHAIN METHOD

Project Masters helps you examine an entire system as a whole, not just the individual parts of the system. We help you keep sight of the big picture.

We use the Critical Chain Method, which is defined as the longest chain of dependent events where the dependency is either activity or resource driven. It assumes that the longest chain is the one most likely to impact negatively the overall duration of a project; it is consequently the leverage point for reducing a project’s duration.

Our services help you:

Improve systems

Recognize dependency variation and finite capacity that exists in the systems

Understand that seemingly complex cause and effect occurs via these dependencies, both in time and in space, (i.e., dynamic complexity)

Increase productivity and output at a constant investment of money, manpower, and machinery. Knowing that variable costs (raw materials) will increase in proportion to output, but operating costs should stay the same

Tips to make your project plan stays in control throughout execution, we help you:

Take all forms of padding out of activity estimates and move to dedicated time estimates.

Level project resources – don’t schedule the project assuming that resource conflicts will resolve themselves. We take care of this up front.

Avoid measuring people on the completion of their activities on time or on the accuracy of their estimates. Instead, we help you reward team members based on finishing the overall project on time or early.

Let people work on Critical Chain activities in a dedicated manner. If someone is schedule to work on one of these activities, let him/her work on it exclusively until it is complete or substantially complete to the point where it can be turned over to the next scheduled resource.

Change your resource management approach so that resources on the Critical Chain have more flexibility to accept work earlier than expected.

Implement a project buffer to project the project’s Critical Chain. This is usually put at the end of the project and is calculated as a percentage of the length of the Critical Chain – usually 30 to 50 percent. It’s a buffer that protects the collection of Schedule Activities on the Critical Chain from any common cause variations.

Implement feeding buffers on any path feeding into the Critical Chain to protect it from variances on the feeding paths.

Here are steps used to help you establish a Critical Chain project schedule:

Identify the Critical Chain – the longest chain of dependent Schedule Activities where the dependency is either activity or resource related. There are two possible paths for each activity: first, what is the next logically dependent activity? – You can’t pour footers until they have first been framed up. And secondly, what is the next activity that uses the same resource as the one where the dependency is therefore a resource dependency? – The procurement person for any project can only order one thing at a time.

Examine – the duration of each possible path and select the longest path based on resource or activity dependency.

Create Buffers – which act as shock absorbers. Reducing overall project risk.

We conduct Buffer Management using the Critical Chain Method

Buffer management is the key to project success. We show project personnel how to examine Buffer reports daily or weekly to determine what actions, are to be taken on the project. Buffer reports for your short projects, less than one month, are examined more often.

Every Schedule Activity is connected to a buffer. If an activity takes longer than estimated, it eats away at the buffer. Buffer penetration reports indicate when the project is in danger and which current activity is causing the problem.

Compare the percent of the buffers used to the percent of the Critical Chain that is completed. If 50 percent of the Critical Chain is completed and only 20 percent of the buffer is consumed, the project is in excellent shape.

Only after a feeding buffer is completely consumed is the project buffer affected. Applied logic used in Critical Chain throughout includes:

Any Schedule Activity on the Critical Chain completed early increases the project buffer time by the same amount. Any Schedule Activity on a feeding path that finishes early increases that amount of time to the feeding buffer assuming of course that the down-stream resource is flexible enough to take advantage of an early finish from a previous activity.

Buffer management should be rigid. The first priority is the current Schedule Activity that is penetrating the project buffer, and the next priority is the activity that is currently penetrating a feeding buffer.

In cases where there are critical milestones, where bonuses or penalties depend on meeting them, there is another priority called the “milestone” buffer. It behaves much like the project buffer. This buffer protects a subset of the project and is almost like a mini-project within the bigger project.

Managing the Execution of a Critical Chain Project

You need to look at all Schedule Activities a given resource pool is working on and set priorities based on the activity that is most penetrating the project buffer.

The information used to generate Critical Chain reports comes from three key pieces of information:

When the Schedule Activity is started

How many days are left to complete the activity

When the activity is completed

Many managers keep track of this information on a daily basis with formal management reports issued weekly. Buffer reports identify whether you’re dealing with a common or special cause variation.

In Critical Chain, the assumption is that a single Schedule Activity has a 50 percent probability of being completed on time. These are very subjective however, and if three or four activities in a row are significantly (more than 5%) exceeding their estimates, other factors such as risk and variability in those types of activities must also be considered.

Where Critical Chain and earned value reporting is used, the reporting should be done only once, but should feed both databases.

Project Masters can help you implement the Critical Chain method on your project.