Down 'n Dirty with TOC and Project Management -- This is the first of a five-part series written in collaboration with Hal Macomber and Joe Ely (I guess it'll really be a 15-part series between the three of us.) on the idea of using the Theory of Constraints (TOC) to help address day-to-day issues, decisions, policies, and practices in project endeavors. You might want to check out Hal's contribution first, since I reference what he has to say about the nitty-gritty of getting stuff done, emphasizing the fact that TOC thinking has more to bring to the realm of projects than just Critical Chain Scheduling and Buffer Management. Being more of a "big picture" kind of guy, myself, I'm going to put some of what he is talking about in a larger context. The reader might want to bounce back and forth between Hal's, Joe's and my weblogs for the next few days to get both the micro and macro views of the story.
While, as Hal points out, "in simplest terms, [one can] think of a constraint as a restriction to flow...[as]...a bottleneck restricts the flow of liquid," one must remember that constraints in a project (or in any other system) exist in terms of a goal. If there is no sense of objective or goal, the idea of a constraint probably does not come into play. But we do projects to accomplish something, and the situation of being "bogged down" is meaningful because we feel that objective or goal is threatened.
If one thinks in terms of the goal of a project as the achievement of its objectives through the delivery of a collection of deliverables, then the primary constraint blocking those objectives is the longest set of dependent tasks required to be performed in their delivery. If that objective has some sort of "ringing cash register" associated with it, then the time associated with those dependent tasks can be considered a measure of the constraint's effect. After all, for many projects, if it can be delivered sooner, a resultant earlier ring of the cash register (or faster "flow" of "rings" in a multi-project environment) equals more "goal stuff." Time is, very often and in many ways, money.
In Hal's first piece, he introduces the idea of a crane as a possible constraint if it is managed in a way that "restricts the amount of work that can be performed in the day." At the day-to-day level, this is an example of a piece of the nature of systems and constraints that is worth expanding on -- that of the layers of "constraints" within the project. These layers might be pictured as...
Layer 1 - The project's "critical" chain of dependent tasksWithin an individual project, as mentioned above, the primary constraint is the longest set of dependent tasks taking us from today to the end of the project, also often known as the "critical" tasks of the project. At a finer level of granularity, the obstacles that are dealt with by the individual tasks can be seen as components of that constraint. And at a particular point in time of the project's life, the ability for waiting tasks to be started is limited by its predecessors and by the resources doing the work. So on the day-to-day basis that we're talking about in this series, the way that currently active tasks (especially the current "critical" task in a formally planned and scheduled effort) are managed and worked can be seen as the immediate constraints to the completion of the project.
Layer 2 - Obstacles dealt with by individual tasks
Layer 3 - Today's active task/obstacle
Layer 4 - Resource availability for and effectiveness in the task
As Hal points out, physical resources in terms of people, space, and equipment can be seen as the finest degree of the constraint that needs to be managed appropriately. And as Joe points out, while TOC and constraint awareness can help direct one's attention to what to improve, "Lean methods" can contribute a lot to how one may carry that improvement (exploitation, subordination, and elevation) out, especially at that level of systemic detail.
I hope you find this week's multi-weblog experiment interesting and of value. Don't forget to read Hal and Joe. If any of what we write triggers a response for you, be sure to note them using the comment feature on any of our sites.
And c'mon back tomorrow for part 2.