The executive summary is the most important part of a business document. It is the first (and sometimes the only) thing others will read and the last thing you should write. It is simply a brief review of the document, given so the busy people who will read your document know at a glance how much to read and what actions will probably be needed.
By now, you’ve probably already read several articles, blogs—even books—about writing the perfect executive summary. Most of them offer a wealth of well-intended suggestions about all the stuff you need to include in the executive summary. They provide a helpful list of the forty-two critical items you should cover, and then they tell you to be concise. Most guides to writing an executive summary miss the key point: The job of the executive summary is to sell, not to describe.
Executive Summary MSc Thesis - Imperial College London
"The most important part of an executive summary is the first paragraph that clearly explains what the company does," according to Dave Lavinsky, president of Growthink, a Los Angeles-based company that helps entrepreneurs develop business plans and raise capital. "Most business plans start with a story that tries to create excitement, and this doesn't always work."