If I had a dime (that’s American $.10 for our international readers) for each time I’ve been asked this question in the past year, I’d have enough to pay for a week’s worth of coffee (and those who know me will tell you that’s a fair amount of coffee!).
This is the topic of some debate.
The accepted answer on the APMP Foundation Level Exam is “5-10% of the overall document, depending on the size of the document.”
Jon and I both see this as too long. Our expectation, from experience both evaluating and developing proposals, is that an executive summary should be between one and a half to three pages. The length should be somewhat longer for very complex responses, but not exceeding four or five pages.
My understanding of how a piece of writing should be was formed in one of my earliest writing classes, probably about the 7th grade or so, when my teacher presented a simple analogy. This analogy has served me well in reminding me to pay attention to the length of what I write.
I have occasionally offered this analogy to people, though I always do so somewhat reluctantly because the analogy is somewhat dated (okay very dated, as Jon will no doubt say!) and, without the proper introduction, it could be viewed as being sexist (it isn’t from my vantage point, but then I never was one for being politically correct).
Recognizing that I’m going to get some flack for it, I offer you the following analogy as regards the appropriate length when writing.
“It should be the same as a woman’s dress. It should cover the subject, but be short enough to be interesting.”
Keep this in mind when you write your next executive summary and I’m confident it will cover the subject and be short enough to be interesting.