This Focused Performance Weblog is a "business management blog" containing links and commentary related primarily to organizational effectiveness with a "Theory of Constraints" perspective. TOC is noted for its applications in Project Management and Multi-Project Management (Critical Chain) and Operations Management (Drum-Buffer-Rope), as well as in Marketing, Strategic Planning and Change Management (TOC Thinking Processes). If you are on an archive page, current postings are found here.
"A Buffer Isn't Padding -- A buffer isn't padding. Padding is extra time added to a schedule that you don't really think you need but that you add just to feel confident in the estimate. Padding is when I take a conventional approach to building a Gantt chart, come up with three months, but tell my boss four months.
A buffer, on the other hand, represents a legitimate expectation of time we expect the project to consume. While I can, if all the stars align, make it to the airport in 63 minutes it would not be prudent for me to plan on that. I should perhaps plan on 90 minutes. If I arrive in 85 minutes I will have consumed 22 of my allocated 27 minute buffer. If I take 95 minutes I will have overconsumed my buffer and will miss my flight. The size of the buffer should be sized based on the duration of the items being buffered and on the consequences of over-consuming the buffer."
I like it. Like I said -- a nice clear explanation -- one that can be used with those that confuse buffers with padding and say "Buffers? We don't need no stinking buffers!"
I'm not sure how Clark found the chapter download, since I can't seem to find the rest of the book. Apparently, I'll just have to wait for Mike Cohn to finish the book in January.
posted by Frank - Permanent Link -
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