Critical Chain Book Summary (Avijit, Mohit, Paritosh)

Critical Chain by Dr. Eliyahu Goldratt Submitted By: Avijit Bajpai (M-11-05) Mohit Pandey (M-11-09) Paritosh Kotwal (M-11-12)

Critical Chain is a book about project management for all the leaders, project managers, operations manager. In this book Dr. Eliyahu Goldratt highlights how the current education system has done more harm than added any value to the individual. The teaching methodology as described in the book highlights how the training and learning should happen in the class via more interactive sessions between the students and the trainer. The book is especially a great value add to Project managers who are in a constantly trying to identify the right things that needs to be done on their projects.

Key Ideas 

A project will run out of time but will never run out of excuses.

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Why are projects late? People blame uncertainty and unforeseen risks. Top management blames externalities, while project participants more-honestly place direct blame on internal politics and management.

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People usually build safety into their estimates when estimating times-to-complete for project activities. Typically, the estimate is judged at an 80% confidence point. That is, the estimator believes there is an 80% chance that an activity will be completed within this time.

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With all this safety built into the scheduling estimates, why are most projects late? Because (1) most safety is wasted and (2) because people do not focus on critical chain activities and resources.

Goldratt’s "Theory of Constraints" (TOC) 1. IDENTIFY the constraint 2. EXPLOIT the constraint (make sure the activity being worked upon, or the constraint, is being done as best possible with the present resources). 3. SUBORDINATE other activities to the constraint. Don’t start activities (production) prematurely. 4. ELEVATE the constraint: Look for ways to shorten the time required at the constraint.

The Critical Chain Approach The critical chain is the sequence of activities—with explicit consideration of constraining resources—that determines the length of the project. The critical chain would be the same as the customary critical path except that some resources may be unavailable when needed. The critical path constraint model is modified to include sequencing scarce resources. 

Use medians for activity estimates (instead of highly confident estimates). Determine the critical path (the series of activities that control the project completion time).

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Put safety into a project buffer at the end of the project. Also put buffers at the end of "feeding" activity paths that merge into the critical chain. The constraint is the critical chain, and this is where most attention should be focused.

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Do not accept "work performed" as project "progress." Project reporting should focus on efficiently accomplishing those activities on the critical chain. Remind people about when their work on critical chain activities is to begin, and ensure that this work begins promptly, has full attention, and is uninterrupted.

Sources of delay in projects Goldratt emphasizes three important ones: 1. The deadline effect (he calls it "student syndrome") describes how we tend to delay starting a task until we "have to." We give ourselves buffer, and then use it all on the front end of a task. (Note that this is typically true for tasks we don't want to do, but not for ones that interest, animate and involve us.) 2. Multi-tasking extends all lead-times. If you're working on something "half-time," it takes twice as long. Or more, due to the overhead of switching from one to the other - "setup time" for "resources." 3. Delays tend to accumulate, advances tend to be wasted. If something in the CP is delayed, the project is delayed. If something in the CP is finished early... the next activity tends to start "on time" anyway.