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Motley says: "If computers can efficiently multi-task, so can I!"

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Summary

 

Motley:  I ultimately finish my tasks sooner by doing multiple things at once. If Microsoft Windows can multitask, so can I!

 

Maven: Work on tasks serially, one at a time. Finish one task before moving on to the next. Context switching severely hurts overall efficiency.

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[Context: Motley and Maven are continuing their discussion Scrum and this time talking about multi-tasking]

 

Motley: What's the problem with doing multiple things at once? I have no trouble keeping a bunch of stuff in my head at once. I do a little bit of one task, a little bit of another task, a little bit of a third, and so on. I finish the set of tasks sooner this way. Can't you walk and chew gum at the same time?

 

Maven: Sure, I can do two things at once, as long as one of the things I am doing is habit and does not require thinking. Walking is habit. I can do it without engaging my brain. I may have to engage my brain to figure out where I am going, but once I am pointed and start walking, I can easily do something else at the same time, like read or listen to music. Once I come to an intersection, however, and have to figure out which way to go, now my brain is engaged, and I stop the other thinking activity, such as reading.

 

Motley: Remember the other week when you were staring at that pretty girl while walking and you ran straight into that pole and bruised your cheek? You're not so good at multitasking are you!

 

Maven: You said you were not going to bring up that incident again.

 

Motley: Couldn't resist. You are easy to make fun of. Anyway, Microsoft Windows is efficient at multi-tasking. I can have multiple processes running at once, which turns out to be extremely efficient much of the time.

 

Maven: It turns out the human brain is not to good at switching thoughts randomly. Here is a quick exercise you can try that proves the point. You need a pen and paper to play along. Got one?

 

Motley: Why would I want to play whatever game you have in mind? I'd rather do magic and make you disappear! Hehehe. Sometimes I'm pretty funny.

 

Maven: Ha ha. Wise guy. This is a really quick exercise that proves a valuable point. You made the claim that you are most efficient doing multiple tasks at once. Let's illustrate what happens when you multi-task-

 

Motley: <whispering> Pssst… Mave. James is listening in again.

 

Maven: It doesn't matter. Maybe he, and whoever he tells this story to, will play along. Anyway, I am going to give you 10 seconds to write down all the letters from 'A' to 'Z' in order. Ready? Go.

 

Motley: <writing>

 

Maven: Stop. How far did you get?

 

Motley: Easy. I almost finished. I got all the way to 'X'.

 

Maven: Good stuff. You're a pro.

 

Motley: What does this prove?

 

Maven: Nothing yet. Let's do part 2. I am going to give you 10 seconds to write down all the numbers from '1' to '99' in order. Ready? Go.

 

Motley: <writing>

 

Maven: Stop. How far did you get?

 

Motley: Is this supposed to be challenging? I'm sure I got more than the average person. I got 21.

 

Maven: Nice!

 

Motley: My patience is wearing thin, Mave. What is this supposed to prove?!?!

 

Maven: One more. Now I am going to double the time to 20 seconds, and you are going to write all the letters from 'A' to 'Z' and numbers from '1' to '99' in order but alternating between letter and number. For example, the list would start out as 'A1', 'B2', 'C3', etc. Ready? Go.

 

Motley: <writing>

 

Maven: Stop. How did you do?

 

Motley: Pretty good. I got to 'M14'. Pretty impressive, huh?

 

Maven: But I gave you double the time as last time. Why didn't you get at least to 'U21'? You got to the number '21' previously. Why couldn't you match it?

 

Motley: You made me do two things at once! My brain has to shift gears every time I go from a letter to a number. Duh!

 

Maven: Exactly! When you change from one task to another, your brain as to make a similar switch in context. But this time we aren't just talking about letters and numbers but perhaps one complex coding task to another. This is why, regardless whether you use Scrum or some other project management technique, you always want to finish the task you are working on before starting another. Have one primary task, and have another one in reserve in case you get uncontrollably blocked on the first one.

 

Motley: You know what I can't stand? You. When you're right. Grrrr. I always tell my team members that they should cut off Outlook, Messenger, alerts, stock quote tickers, etc. that provide constant interruptions when they are trying to get in the "zone" to get some real work done. It boils down to the same reason. I must not have had my morning caffeine today. I apologize for that.

 

Maven: No problem. Computers are good at multitasking within certain constraints, but we're not so hot.

 

Motley: Actually, computers aren't that great either. If you design an application that uses too many threads and the operating system has to keep switching between them, the context switch is significant overhead and may involve paging memory on and off disk. Same concept. Of course, we can have computers with multiple cores and if we create one thread per core with nothing else going on, then multitasking can be efficient. I guess that is the equivalent of having two brains, though.

 

Maven: Nice. Great point there Mr. Motley.

 

Motley: I'm full of good tidbits.  Now, if I can only do one thing at a time, I choose getting some real work done over talking to you. Goodbye.

 

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Maven's Pointer:  Recently we talked about data gathering with Scrum, and analyzing Burndown charts with Cumulative Flow Diagrams (CFD). One characteristic of the chart to pay attention to is a wide yellow section representing in-progress tasks. If the team has too many in-progress tasks, it is likely not being as efficient as it could be.  Keep the number of in-progress tasks to a minimum to ensure the team is not multitasking. Each team member should work on one task, and have a back-up should they get blocked. The yellow section on the CFD should be as thin as possible.

 

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Comments

  • Anonymous
    February 27, 2008
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