Down 'n Dirty with TOC and PM (Part 3) -- In this little collaboration with Hal Macomber and Joe Ely, I wonder if I really have to say more about multi-tasking, the subject of a lot of my recent weblog postings, and I will admit, something that is a bit of an obsession with me. Maybe I should simply address Hal's closing admonition and question...
"Do not let them start one task before they finish the task they are working on. Sound crazy?"
...with a suggestion to carefully consider the implications of the following simple picture...
In which a simple "third of a headcount" assignment to three tasks of similar duration doubles (at least) the completion time of the first task, delays the completion of the second despite getting started on it earlier than if it waited for the first to complete, and does nothing to help the completion of the third. Actually, once the effect of context switching is added to the picture, all three tasks will be delayed even more before they can hand off their outputs so that those who use them as inputs can do their bit for the project.
Actually, in a lot of project situations, especially multi-project environments, but also in single projects, multi-tasking can be pointed to as the biggest waste of time and source of delaying constraints. In a multi-project environment, where resources are shared across a number of projects, the most common source of multi-tasking is an uncontrolled launch of work into the system, and as Hal suggests, the desire to keep everybody happy.
In individual projects, however, we come back to the discussion of dependent tasks I introduced in the first day of this series. Most people, when laying out what is involved in a project, will draw a network of dependencies that link tasks by the hand-offs -- the outputs of predecessors that are inputs for successor tasks. In order to assure that the promise of a project is not erroneously made with "resources in contention," setting up pressure to multi-task and exacerbating the inability to deliver on that promise, the identified constraint of the project -- the critical chain of dependent tasks leading to the project goal -- must include both hand-off dependencies and resource dependencies.
On the day-to-day level, it's important to remember not to pressure your resources to split their focus, and instead, provide as clear a set of priorities as possible for them, so they don't have to come back and ask "What DON'T you want me to work on?" After all, one of the most important questions that is answered by effective management in general, and project management specifically, is "What should I/we be working on?"