For the Multi-taskers out there, here's a great post that describes a game you can try at home to measure the effect of context-switching on productivity:
Here's a quick exercise to show you the cognitive penalties for you, personally, to context.
You will need a pen, a pad of paper, and a timer.
Now on this pad create three columns [...]
Now get your timer ready.
In each column, we?re going to write a letter, a number, and a then a roman numeral ? in that order. [...]
We want to do this to the letter "J".
Again, we want to do A, 1, I, B, 2, II, C, 3, III, ?.
Start your timer, do A through J, and then mark down your time.
Now, do that again, but do the letters, numbers, and romans in sequence. So this time do A, B, C and on to J, then the numbers in order, then the roman numerals.
Set your timer, do this, and then mark down your time.
The point is, context switching costs you. Something to remember when loading up your most valuable players with too many projects.