Critical Chain Project Management: A Summary of Motivation and Overview

Traditional Project Management Methods Don’t Account for Everything

This blog provides an overview of Critical Chain Project Management (CCPM), highlighting the motivations behind its development and its core principles. Traditional project management methods often fail due to inherent behavioral issues and a misunderstanding of how to handle uncertainty. CCPM offers a different approach to project management that addresses these shortcomings.

The Core Problem: Project Failures Despite Contingency

Project management involves balancing commitments related to schedule, budget, and scope under conditions of uncertainty and complexity. Despite employing formal project management practices, a high rate of project failure persists across industries. Part of the  reason for this failure is the paradoxical situation where projects fail despite having built-in contingencies.

Traditional project management relies on creating a project plan that models the logistical process required to deliver the project scope. This plan includes contingencies in the form of extra time and budget to accommodate unexpected events. However, the pressure to minimize costs and time often leads to disguising these contingencies within individual tasks. Project managers embed enough safety in each task to ensure a high probability of on-time and on-budget completion.

The existence of these hidden contingencies leads to specific behaviors among project team members that ultimately undermine project performance.

The Root Causes of Project Failure: Undesirable Behaviors

Three main behavioral issues that contribute to project failures:

1. Procrastination (Student Syndrome): This refers to the tendency to delay starting a task until the last possible moment, even when there is ample time available. The existence of contingency within a task creates a false sense of security, leading individuals to postpone work until the deadline approaches. The problem with this approach is that if any unforeseen problems occur towards the end of the task, the individual has no additional time to resolve the issue, and the task ends up being late.
2. Parkinson’s Law and Failure to Report Early Completions: Parkinson’s Law states that “work expands so as to fill the time available for its completion.” In a project context, this means that resources will often take the entire allocated time to complete a task, regardless of whether it is strictly necessary. This is often coupled with a reluctance to report early completions, driven by a fear of being perceived as having “sandbagged” the estimate (i.e., intentionally inflated the time required). Additionally, any unused budget from a task may be used to cover overspending on other tasks.
3. Multi-Tasking: In many project management environments, resources are shared across multiple projects. While this is intended to maximize resource utilization, it often leads to multi-tasking, where resources are forced to switch between different tasks before completing them. Multi-tasking introduces significant overhead in terms of context switching and lost focus, ultimately delaying all the projects involved.

The Critical Chain Solution: A Different Approach

Critical Chain Project Management (CCPM) offers an alternative approach to project management that aims to mitigate the negative effects of these behavioral issues. CCPM focuses on:

1. Identifying the Critical Chain: Unlike the Critical Path Method (CPM), which only considers task dependencies, CCPM identifies the longest sequence of resource-constrained tasks. This critical chain represents the most important path for ensuring project completion on time.
2. Aggregating Contingency into Buffers: Instead of embedding contingency within individual tasks, CCPM removes the safety time from each task and aggregates it into project and feeding buffers. Project buffers protect the overall project completion date from delays on the critical chain. Feeding buffers protect the critical chain from delays on non-critical paths.
3. Buffer Management: CCPM uses buffer consumption as a primary indicator of project progress. By monitoring how quickly the buffers are being consumed, project managers can identify potential problems and take corrective action before they impact the project schedule.
4. Prioritizing Critical Chain Tasks: CCPM emphasizes the importance of focusing resources on tasks along the critical chain. Resources should be dedicated to these tasks and should not be multi-tasking on other tasks.
5. Managing Resources: CCPM recognizes the importance of effective resource management. Project managers need to ensure that resources are available when needed and that they are not over-allocated to multiple projects.

How CCPM Addresses the Problem

CCPM directly addresses the issues caused by traditional project management practices:

• Procrastination: By removing the contingency from individual tasks, CCPM reduces the incentive to procrastinate. Tasks are estimated based on the average time to completion, encouraging resources to start working on them promptly.
• Parkinson’s Law: The focus on buffer consumption encourages resources to complete tasks as quickly as possible, rather than simply filling the allocated time. Since there is no local contingency, any time saved on a task directly benefits the project as a whole.
• Multi-Tasking: By prioritizing critical chain tasks and focusing resources on them, CCPM reduces the amount of multi-tasking. Resources are dedicated to completing critical chain tasks before moving on to other tasks.

Real-World Benefits

Studies have shown that CCPM can significantly reduce project duration and improve on-time performance, results have been seen from 10% to 50% faster and/or cheaper. CCPM offers a valuable alternative to traditional project management methods. By addressing the underlying behavioral issues that contribute to project failures, CCPM can improve project performance and increase the likelihood of successful project completion. In essence, Critical Chain Project Management acknowledges the inherent uncertainties and human behaviors that often plague project execution. By strategically placing buffers and focusing on the critical chain, CCPM offers a more robust and effective approach to project management, leading to improved efficiency and on-time delivery.