Last month I read

• Critical Chain from Eliyahu Goldratt
• What would I be without you from Guillaume Musso which is not the topic of this article.

I really love Eliyahu Goldratt’s business novels, these are not only easy to read books but they are also very rich in content.

After having read two of his previous books, The Goal and It’s Not Luck, I hoped to learn a lot again. And I did! Below is a TL;DR and some takeaways.

ROTI: 4/5

ROTI: Return on time invested.

What you will find in Critical chain

It explores why projects are often late even though people take 200% buffer in some areas. It explains the topics of the different diagrams PERT / Gantt but also the concepts of critical path, critical chain, buffers:

• resource buffer,
• feeding buffer,
• project buffer

There is a lot of emphasis on project focus and how people should not multi-task and how important this is in order to save time.

It also makes the reader think of what could be done and talks about some pitfalls that the different projects fall into. Some solutions are brought to face these pitfalls by visualising who does what and to be able to identify the critical chain and how to protect it using Post-its and color cards. It also brings on the table how to work with several projects interacting together. The book being written with characters discussing problems makes the reader think about the topics in a more engaging way.

On top of that the author refreshes the reader on the Theory of constraints, which is explained in The Goal, and he uses the Thinking Processes in order to find and demonstrate the solutions.

In my opinion if you are interested in project management there are a few visualisation techniques and concepts to take from this book.

TL;DR

The whole intention of a project is to make money not to save money.

If a project manager starts too many things he loses focus, and he and his team cannot afford that.

What is usually common to all projects, no matter the industry?

• Budget overruns
• Time overruns
• Compromising the content

What are the official reasons? What are the unofficial reasons? What do you think you would find if you were to compare these reasons?

The book gives a list of them, and to be fair I think I have heard almost all of them in the past. Nonetheless, it would still be very interesting to do the exercise on ongoing projects.

One of the key problems of all projects is uncertainty. Uncertainty is in every project. In IT even more than in other industries I reckon.

Goldratt then explores 3 mechanisms by which safety is inserted into the time estimates of almost every step of a project, and some mechanisms that waste this safety.

There is an analysis of the control and measurements and how often these numbers do not show how late the projects are. In the end we find a possibly better approach which consists on measuring the Critical chain not the critical path and measure the time left in the buffer.

The author looks at the Pareto’s principle and shows why we should be careful about it. Pareto’s principle in brief is about focusing. Focus on 20% of the problem and 80% of the work will be done. This actually works for independent variables (in mathematics), and it works in the cost world where everything is managed individually.

A few solutions are proposed to remove the 3 ways of wasting buffer that were discussed previously in the book. Two of them are to not base the start, and the end of steps in a project on milestones but that as soon as a step is done, move on to the next one. Then, remove the false alarms and noise on the possible late paths. This reduces multi tasking and helps to improve the lead time, and the people to be more focused.

Last but not least, one key information to take away from the book in my opinion is the finding of the critical chain in your project, and how to put the buffers correctly. There are a few examples in the book and by the end we finish with this list of possible buffers:

• resource buffer
• feeding buffer
• project buffer

I really recommend reading this book if you are into project management there is a lot of information and makes you think about how to make things better.

Hope this helps.