In this posting we’re going to discuss just how negative the effects of bad multi-tasking can be and how it can negatively impact projects’ on-time completions.
Bad multitasking happens when resources are forced to work on multiple project activities at the same time. Many people believe (especially in leadership positions) that multitasking is a good thing because it increases efficiency since everyone is “busy” all of the time. If you’ve ever read The Goal by Eli Goldratt (if you haven’t, you should), you might remember how focusing on driving efficiencies higher on every part of a process, actually damages the overall system . You may also recall how Goldratt used his robot example whereby running the robots continuously, efficiency did improve, but at the expense of creating mountains of excess inventory. The negative impact of bad multitasking in a project management environment is much, much worse. Let’s look at an example.
Suppose you have three projects (see Figure 1) that you are assigned to complete and in each project you have estimated that you need 2 weeks (10 days) of work on each project for the tasks assigned to you. Assuming Murphy didn’t strike, if you started and finished Project 1 without stopping or working on any other project, it would be completed in 10 days. Ten days because that’s what you told everyone it would take (Parkinson’s Law). But having laid it out like this, if all three projects were scheduled to start on the same day, then Project 1 would be on time at 10 days, Project 2 would be done in 20 days, but would be 10 days late and Project 3 would be done in 30 days but would be 20 days late. Likewise for Projects 2 and 3, assuming no other interruptions, each would take 10 days to complete for a total time to complete the three projects of 30 days. But CPM doesn’t usually work like this in a multi-project environment.
Because there are probably three different project managers, each one is most likely telling you (or maybe even screaming at you) that they need you to show progress on their project (remember, projects are typically measured by % of tasks complete versus some due date or tasks left to complete). Because you want to satisfy all three project managers, you decide to split your time between the three projects (i.e. you’re guilty of bad multi-tasking). So as is demonstrated in Figure 2, you start with Project 1 and work on it for 3 days. On the fourth working day, you begin Project 2 and work on only it for 3 days. You repeat this sequence until all projects are completed.
By using bad multitasking, look what’s happened to the time to complete each individual project. Without bad multi-tasking Project 1 took only 10 days to complete, Project 2 was completed in 20 days and Project 3 took 30 days to complete. Remember, all 3 projects were scheduled to start on day 1. With bad multi-tasking Project 1 took 28 days, Project 2 took 29 days and Project 3 took 30 days, again with all of them finished in 30 days. Both methods completed all three projects in 30 days, but which set of results do you think your leadership would prefer? Having two projects done in 20 days and the third one at the 30 day mark or the results of bad multitasking? Keep in mind also, that when you are guilty of bad multitasking there is also time required to get re-acquainted with each project so the multi-tasking times will actually be considerably longer. In fact, some studies have shown that tasks often take 2-3 times their estimated duration when multi-tasking occurs.
Before me move on, let’s summarize what we’ve learned so far. We’ve learned that task time estimates for tasks are artificially lengthened as a protective measure against Murphy and all of the negative baggage he brings to the party. We’ve learned that even though this safety is built in, it is wasted because of the Student Syndrome and Parkinson’s Law. With the Student Syndrome we put off work until the last minute, while with Parkinson’s Law we use all of the time allocated even if we finish it early. And finally we’ve learned how devastating bad multi-tasking can be to the completion rate of projects and if we could eliminate it, we know our on-time completion rate will improve. Although eliminating bad multi-tasking improves our on-time completion rate, are there other things that can be done to improve these rates even more?
In my next posting we’ll look at other important things that can be done to drastically improve project completion rates.