The Established Theory
In most organizations, this is a very difficult concept to change. It is well ingrained that multitasking is good and expedites work. However, dedicating resources maintains focus, increases efficacy and reduces frustration. Management puts forth the most resistance to dedicating people to tasks. They want to preserve the concept of multitasking so they have the flexibility to quickly reassign resources. What seems odd is that in organizations that insist on multitasking, they still fall back to one common practice—if a project gets in trouble, they immediately ask that resources be dedicated to their tasks. Down deep, management understands that multitasking is inherently inefficient.
Team members love being dedicated to their work. They know they will work more efficiently and with less frustration. Stopping and starting the task adds significant time and risk.
A Simple Example
Critical Chain and Agile methodologies require dedicating resources. Many supporters use an example like that shown in Figure 1. It is the classic diagram to show the effect of multitasking. It shows three separate tasks, each two weeks long, being done by the same person all needing to be done at the same time. In the upper case, the person multitasks. All tasks are late. Task A is completed two weeks late, Task B is three weeks late and Task C is four weeks late. The average is three weeks late.
In the lower case, the person is dedicated to the tasks and perform them uninterrupted. Task A is done on time, Task B is done two weeks late and Task C is done four weeks late. Only two tasks are late, the average being two weeks late, a week earlier than multitasking.
Comparing the two concepts in another way, Task A is done two weeks earlier than when multitasking (actually completed on time), Task B is done two weeks late (a week earlier than when multitasking) and Task C is four weeks late (no different than when multitasking). This simple diagram shows how poor the concept multitasking is.
Where is Common Sense?
Common sense backs up the studies. However, common sense seems to be failing in most organizations. What managers need to do is to assign priorities to the work and stop the interruptions. Close examination of many of the interruptions shows that knee-jerk reactions, asking people to switch tasks, are made with too little data. The key to well run organizations is allowing people to complete their current assignment before switching to a demand driven task.
About That Gender Bias
Back to the opening premise about men being poor at multitasking, this is a classic sexist comment, not about men, per se, but about homemakers. Yes, it comes from the fact that most women are homemakers, even if they haves a full-time jobs. The homemaker (male or female) has to multitask. Efficiency is of minimal concern, the home is. If the two year-old center of your life is about to climb the book shelf, grab a butcher knife, pour super glue on your cell phone or feed oatmeal to the DVD player, the effective homemaker better stop doing bills and switch tasks at a instant’s notice, diverting the required attention to the little bundle of joy. It may take longer to do the chores, however potential disaster is averted. As my dear Mom used to say, "The housework will still be here tomorrow."