PMI New Jersey Chapter
PMINJ 2000 April Meeting

18 April 2000 - Somerset - Marriott


PDP Information

Program Number: C020-17042001
The Application of Critical Chain Project Management to Multi-Project Environments
Category Type: 3 
Subject Areas 
Knowledge: 1, 3, 5, 6, 8 
Process: 2, 3, 4
Application/Specific Interest Groups: 30 
Activity Sponsor: PMINJ Chapter (C020)
PDUs: - 1.5
Leadership - 0.0
Strategic - 0.0
Technical - 1.5


Today's multiple project environments generate multiple priorities for project resources and managers. These competing priorities cause a loss of focus and contribute to the inability to complete tasks (and projects) on schedule. The Theory of Constraints (TOC) is a philosophy of management and improvement characterized by its recognition of the interdependent nature of complex systems like organizations and projects. Applying TOC to project management has resulted in the methodology known as Critical Chain Scheduling and Buffer Management and its extension to program and multi-project management. This program will discuss project management solutions based on these concepts. 

Additional Answers to questions from the meeting: 

>* Sure wish I could have had my question answered. How do you prevent initial tasks from using up the entire available buffer? 
You manage the project by managing the buffer.  The buffer is not only a static demonstration of the health of the project; it is used during project execution to highlight that attention must be paid to a project that might be in jeopardy. If you still have the handout (If not, check out <>), look at the slide on buffer management where you can find a paper related to the presentation), showing the breakdown of the buffer to OK, Watch & Plan, and Act sections.
If the buffer starts to get consumed in the early going, you would rightfully be concerned if it were allowed to be 33% consumed with only 10% of the critical chain completed. I like to advise my clients that in the early going, buffer management be used almost like an SPC (statistical process control) control chart. If the project buffer is consistently being consumed at a faster rate than critical chain is being completed, that trend can also be an indication that a corrective action or "proactive reaction" be developed to replenish buffer.
If frequently and regularly updated and reviewed, buffer tracking allows visibility to trending situation, heading off surprises (allowing one to "panic early," as I mentioned in the presentation), and planning corrective actions in an environment that is not characterized by crisis. 

>* Good topic but difficult to implement
>* Seems like a very difficult paradigm shift
>* Good point about the need to get top down buy in to approach, to make it work 
These comments were all concerns about buy-in to the ideas and obstacles to implementation. With a carefully designed program of leadership buy-in, just-in-time education, development of internal expertise, and phased roll-out, it is usually implemented with all current projects re-planned for the process in about 3-4 months.
It involves not insignificant attention, but I wouldn't call it difficult. 

>* Unfortunately I doubt my [company name deleted] management would ever embrace such a great concept as this. 
This is a very common obstacle -- not management, but the convinced PM's doubt that they would be receptive. Not all management are like the pointy-haired boss in Dilbert. Many people like the writer can often be pleasantly surprised by management's response to a presentation of the concepts, as long as that presentation is put forth in terms of problems that management identifies with. Actually, when it comes to multi-project environments, management usually has the best big-picture view and understanding of the impact on the larger organization's ability to get more throughput. PM's usually focus on their own project and resources usually focus on the technical aspects of their tasks. Management is usually given insufficient credit for the ability to recognize common sense. If you don't ask them to consider something that makes sense, you're not giving them a chance to surprise you. 

>* I do not have any control over resources on who works on what task 
What PM really does? As a matter of fact, the PM shouldn't have such "control" where resource managers have the best perspective on capability and availability of resources. If there is concern on the part of a PM on this issue, I would think that the recognition of potential variability in the scheduling process and the robustness of the use of buffers for real and visible management of the project promise will help in environments where the PM doesn't "control" resources. 

>* What type of projects would this work on. Need example to understand
>* TOC is difficult and requires a better build up. More specific real life examples should be added. The other discussion would be how much is TOC validated by actual projects? (2) 
More and more companies are starting to be willing to talk about their success in implementation of critical chain and critical chain-based multi-project management.the following list should provide a sense of the type of projects to which this has been applied: 
  • Reflectone/British Aerospace - Commercial/military aircraft simulation systems (flight simulators)
  • Lucent Technologies - Product development in a variety of business units (One unit went public at a presentation at a recent Management Roundtable conference on product development)
  • Seagate - Computer storage systems (also a recent Management Roundtable)
  • Synergis Technologies - Automotive sheet metal stamping die design, development, and manufacturing
  • Elbit Systems - Israeli developer and integrator of "high-tech" military system upgrades
  • Seabridge/Siemens - telecomm switches
  • Lord Corporation - Internal business IS services
  • Balfour Beatty - UK Civil engineering, road building
  • Harris Semiconductor - Single Project for construction of a semiconductor fab facility, multi-projects in development
  • ITT NightVision - Product development, in effort to shift from military focus to more commercial applications
  • Better Online Systems - Israeli software developer for mid-range IBM systems
Details on most of these are available either on videotape or online in the "Success Story" portion of the Goldratt Institute website, found at

>* Feel that it really not appropriate to project with controlled due date 
If I'm interpreting "controlled due date" correctly, I'm not sure where the concern is. In the Critical Chain methodology, there is a solid due date at the end of the project buffer -- one that is rational, yet is usually 10-35% closer to today than in a traditional schedule where safety is spread out among the tasks. As the schedule chains complete in more or less time than originally modelled (which we expect to happen), the buffer is consumed or replenished at the front end. The buffer is solidly anchored at the due-date end. The buffer flexes like a shock absorber so the due date doesn't have to move. 

>* I anticipated that there would be more sophisticated examples of critical chain concepts (but maybe it would have been too difficult to comprehend).
>* Would have benefited from clearer examples. More contrasts of standard scheduling & resourcing would have been helpful. 
With only about an hour for the presentation, and with an audience with various levels of familiarity with the topic, the objective was to introduce the concepts. More difficult examples would raise more noise in such a presentation than would be worth the effort to get around. If anyone is interested, there are half-day and 2-day presentations (including the one mentioned in the "filler text" on the multi-tasking exercise handout) available that include considerably more complex examples, simulations, and exercises.

Frank Patrick, Focused Performance 


Frank Patrick is founder and principal consultant of Focused Performance and a Certified Associate of the A.Y.Goldratt Institute. Focused Performance and AGI provide management consulting, training, and facilitation that assists organizations in the application of the Theory of Constraints. Frank's experience over 25 years has taken him through Industrial Engineering, Total Quality Management, Business Process Reengineering, and the Theory of Constraints. In addition to presenting workshops, seminars, and implementations, Frank is also a regular speaker on TOC topics at such professional associations as APICS, ASQ, IIE, and PMI. 

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