Review #2 – Critical Chain

Author: Eliyahu M. Goldratt.

Genre: business fiction.

Target Audience: business professionals, particularly those that manage projects, work on projects, or have a stake in the outcome of projects (i.e., almost anyone in business!)

Length: 246 pages.

First Published: 1997.


This is another book by Eli Goldratt, who authored the last book I reviewed, The Goal (and yes, I read and will review books by authors other than Goldratt). Critical Chain Project Management (CCPM) may be one of the most effective project management methodologies you have never used (or heard of for that matter). While The Goal changed the way I think about how businesses operate, Critical Chain changed the way I think about projects.

There are many project management methodologies that are well-documented. However, many projects – if not most projects – do not finish on-time (at least the original due-date). Often, they are delayed by months or even years – if they finish at all. In this book, Goldratt introduces an alternative methodology in the form of CCPM that can improve significantly project due-date performance.

The Theory of Constraints (TOC) views operations as chains. The products or services a company provides to its customers are the output of those chains. Projects are chains as well. The widely-used critical path project management methodology can be defined as “the longest chain of dependent tasks.” That includes the dependencies between tasks, which are accounted for commonly on projects.

However, there is another type of dependency, namely resources, that are not accounted for commonly on projects. On most projects, there is an implicit assumption that resource availability is infinite. As a result, projects are planned with tasks that are scheduled concurrently and require the same resources, thereby promoting bad multi-tasking and leading to project delays. Critical Chain accounts for task dependencies and resource dependencies.

The idea is simple. So why isn’t it used more frequently. I think it’s because there are many psychological factors that are implied in the way we manage projects that have gone unaddressed for years. Goldratt addresses several of these.

For example, when estimating the duration for completing a task, most people will make estimates based upon their worst, passed experiences. Either consciously or unconsciously, they embed safety or cushion in their estimate of the task duration. Often, they provide a task duration estimate that includes cushion that allows for up to a 90% level of confidence – or greater – of completing the task on-time. They do this because they want to minimize the possibility that they don’t complete the task on-time and are punished for not doing so.

If all tasks have so much cushion embedded in them, then why don’t projects finish on-time more often?

First, people know that the duration of their task estimates may be cut by their boss or the project manager, regardless of the initial estimates they provide? Therefore, they overestimate with the expectation that their estimates will be cut.

Second, there is a phenomenon known as the “student syndrome.” When people ask for and are granted more time to complete a task, they typically don’t take advantage of the extra time by getting started right away on the work (I’m sure you can’t relate to this).

Third, when people do finish a task sooner than they estimated, they don’t notify their boss or the project manager. They know that if they go back to their boss and say it took half as long as they estimated, then the next time they will be held accountable to completing work in half the time (I’ve seen a similar phenomenon regarding the use of budgets). Therefore, they may spend an inordinate amount of time polishing up the work when the juice isn’t worth the squeeze. This is known as “Parkinson’s Law.”

What’s amazing to me is how simple and powerful CCPM is. What’s even more amazing is how infrequently it is used, given that there is a historical track record of over 20 years of CCPM being applied successfully to improve significantly due-date performance.

Lastly, like The Goal, this book is written as a novel, which makes it much more fun to read than most business books.

If you work for a company that executes projects regularly and you have a stake in the outcomes of those projects, I strongly recommend you read this book.

Buy It Here!

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