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.
Thursday, October 23, 2003
Stage Gates and Critical Chain -- In a recent Sciforma Q&A column by Harvey Levine, the following question and answer about stage-gates, critical chain-based project management, and milestones appeared...
"I work for an Electronic High Tech firm and currently we utilize a Stage-Gate process for our NPD and have been researching the benefits/limitations of the ToC. In your paper you mention both and I would like to know if these can co-exist? From my research to date, it appears to me that the Stage-Gate methodology of NPD process management can co-exist with a ToC based task scheduling model? Can you advise?
...I assume that by "TOC" you mean that you are using critical chain methods. The early concepts for CCPM, as expressed by Goldratt, discouraged using milestones. Yet, milestones are at the very foundation of Stage-Gate. So, in theory, we could believe that TOC and S-G are incompatible. However, in reality, I think that this is not true. In practice, many CCPM implementers have ignored the original taboos that were proposed by TOC proselytizers and have incorporated most of the traditional CPM-type capabilities. While I cannot spell out the specific means of using CCPM with S-G, I can't see why these two processes cannot co-exist.
I'm in general agreement with Harvey's comments in the Sciforma Q&A column (although I'd be curious to hear from him more about the "CPM-type capabilities" he mentioned being incorporated by CCPMers -- I've dropped him an email query on the comment; if he responds, I'll pass it along), and offer a couple clarifications on the core topic from the CCPM perspective...
Early talk about milestones in the CCPM community should have drawn a finer distinction between "milestones" and "milestone schedules." Like the concept of "efficiency," the idea of milestones has had unnecessary abuse heaped on it by too many of my TOC brethren, especially those who, satisfied with the success provided by TOC solutions, fail to look beyond to the core concepts and definitions of preceding bodies of knowledge.
Milestones, aka, specific events of special importance -- such as stage gates -- are facts of life in a project, totally consistent with CCPM, and pose no problem whatsoever in the use of CCPM. The idea of pinning those milestones to target dates via a "milestone schedule," however (or of considering target dates for any task for that matter), leads to a setup for the impact of Parkinson's Law. Date-driven Milestone Schedules should be avoided if speed of delivery of the overall effort is important. What we want is a relay race, not a train schedule punctuated by stage gates attached to the calendar.
If there is some rare real reason to identify a target date with an intermediate milestone (usually some promise external to the flow of the project not associated with the completion of the project), that date would/could/should be buffered in the same manner as the final project promise date, with a "project buffer." Otherwise, stage-gates should float in time, uninhibited by any bogus "good enough, on-track" time targets, so that they can take advantage of early completions and avoid driving questionable quality. After all, the work is going to take as long as it takes. If the project environment assures efficient and effective behaviors in performing project tasks, unhampered by false priorities of task/milestone due dates, then the stage gates will be arrived at in a timely manner.
Effective projects are not about the schedule and plan. They're about the behavior and the work, and control mechanisms that don't get in the way of speed or quality and how, when faced with reality, performance matches or deviates from (or needs to detour around) the expectations that are the schedule and plan.
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