December 2, 2007 | Author: PM Hut | Filed under: Scheduling
A Project Management “Truth” or Statement for Critical Chain Scheduling and Buffer Management
By Greg Phipps
What do you mean “Two Weeks”?
Not really trying to sound “ancient” here, but during decades of doing project management, I’ve learned to really appreciate the concept behind the Critical Chain Scheduling and Buffer Management methodology. I fact, in the early years (late 1970’s to mid-1980’s) I called it “resource dependency” … and there were not any software tools to assist in the effort.
The early years were a time of complete stress when attempting to create a project plan (or Gantt chart). Accounting “columnar graph paper” was used to draw out the project time line to determine “critical path” tasks.
The columnar graph paper was the pencil & paper version of the spreadsheet today. In fact, a “killer app” called “VisiCalc” was one of the first “row/column tabulation” programs (or spreadsheet applications), introduced in the late 1970’s by co-creators Dan Bricklin and Bob Frankston; helping to define “personal productivity”.
The first project management software tool that I used in an attempt to create a Gantt chart was VisiSchedule; in the early 1980’s. The software ran on one of the first color IBM PC’s (a dual 360-floppy system). It handled task dependencies fine, but the screen colors were hard to read (yellow letters on lime green background) and there were storage limitations that affected the size of the project plan that could be built. After trying to use the application for about one week, I went back to pencil & paper.
The analysis of project management showed me that the best approach for me was to “tailor” the appropriate methodology to fit the organization, staff, and type of project involved.
It was learned early in my career that it would be difficult to keep up with the “correct” current changes in technology … especially when then the company was not interested in being on the “bleeding-edge”. The common area in every project was the management of that project; so I focused my energy of the methods and techniques of project management. I approached the study or project management like I did business analysis … I identified the routine to determine the exceptions; so that the exceptions could be categorized and prioritized.
Well, back to the topic of Critical Chain Scheduling …
There was a saying many years ago that “a poorly planned project takes three times as long and a well planned project takes “two times longer”. Knowing that it is difficult to “predict the weather”, how do you do a better job at outlining a project and determining the finish date? There are a lot of theories and techniques out there.
Just like everyone else, when asking team members for estimates for the tasks to be performed, I would factor in some kind of a buffer. This buffer would allow for all of the different types of interruptions. As the team members were asked, more and more, to work on multiple projects, those “interruptions” were more significant and harder to control and estimate.
Recently, I read an article on the internet called “Critical Chain Scheduling and Buffer Management . . . Getting Out From Between Parkinson’s Rock and Murphy’s Hard Place”. It is located at http://www.focusedperformance.com/articles/ccpm.html. This was a great article that puts the methodology into perspective.
During many years of “corporate consulting”, I have used this technique for the smaller, two to five team member, projects. The success has been significant, but not to the point of convincing most business management that, in some cases, the method could be used for the larger projects.
The primary obstacle seems to be that it is difficult for business management to not think in terms of task completion dates and let the project manger report on buffer status. Some other obstacles include, team members multitasking, resource contention, improper management of estimating tasks without buffer time and the calculation of remaining time to complete the tasks.
This concept of project management is a real change in the corporate culture and that takes time to establish. A recommended approach would be to start with the small projects with the smaller number of team members. Remember, when you begin, you will be training the staff, management, and yourself on the concept. The key is to be flexible, but persistent.
Critical Chain Scheduling can be a very effective methodology, but all of management must be willing to learn to only focus on the finish date of the project, not the tasks, and use the buffer status reporting properly. Project managers must learn to alter their management style and approach when determining the status of the buffers within the project.
Learn to determine the appropriate project management tools and techniques and do not be afraid to alter some of the “defined tasks” to suit your situation once you understand the process, the organization, and your team members.
Greg Phipps … is a father and husband; married to the same woman since 1974. He has been performing project management and business analysis for over 30 years in many different business environments.
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