|Critical chain project management reduces project schedules and uncertainty.||
CRITICAL CHAIN PROJECT MANAGEMENT
Product development projects, like many other types of projects, often can exceed their planned schedule by 50% to 100%. Often this is attributed to uncertainty or the unforeseen. To compensate for this age-old dilemma, managers and project personnel have learned to compensate by adding additional time to their schedule estimates. Yet even when they do, projects still overrun their schedules.
The Critical Chain Method (CCM) or Critical Chain Project Management (CCPM) is an outgrowth of the Theory of Constraints (TOC) developed by Eliyahu Goldratt to scheduling and managing manufacturing. TOC focuses on identifying and fixing bottlenecks in order to improve the throughput of the overall system. Likewise, Critical Chain focuses on bottlenecks. For example, one pharmaceutical company was experiencing significant delays with drug approvals. After investigation, it found that the bottleneck was statisticians to analyze clinical trial data. The cost of hiring statisticians was more than offset by the revenue from getting products to market sooner.
Using the Critical Chain Method, projects can be completed more quickly and with greater scheduling reliability. The difference between traditional and Critical Chain scheduling is in how uncertainty is managed. In traditional project scheduling, uncertainty is managed by padding task durations, starting work as early as possible, multi-tasking, and focusing on meeting commitment dates. The following bullet points illustrate some of the problems associated with traditional project scheduling:
Given the these issues, itís not surprising that the most projects are always late.
In Critical Chain scheduling, uncertainty is primarily managed by (a) using average task duration estimates; (b) scheduling backwards from the date a project is needed (to ensure work that needs to be done is done, and it is done only when needed); (c) placing aggregate buffers in the project plan to protect the entire project and the key tasks; and (d) using buffer management to control the plan. The key tasks are those on which the ultimate duration of the project depends, also known as the Critical Chain.
The specific steps to identify and manage a Critical Chain schedule are as follows:
To support Critical Chain Project Management, specialized CCPM software tools are needed to implement this philosophy. These software tools can work in conjunction with popular project management software such as Microsoft Projectģ.
The Critical Chain approach is perhaps the most important new development in project scheduling in the last 30 years. Used properly, the Critical Chain approach is an extremely powerful means of gaining more predictability, productivity and speed from your project plans. It has been found to be an effective tool to protect projects from uncertainty and the effects of Murphyís Law.