Usually when you write a detailed report such as a research paper or a business plan you will need to provide an executive summary at the beginning of your report. If the detailed report is a team effort then a member of the team could be assigned to write the executive report. If you're the only one who did the report then you'll have to do it yourself. The executive summary contains the main points of your report that you would want any reader of the report to know about. Normally the executive summary is the last piece of work you do before completing and submitting you report. You can also look at it as a half or one page report that summarizes the detailed report for someone who is too busy to read the whole report. Perhaps that is why it is called an executive summary, because top level executives are busy people who don't have the time to go through the whole detailed report and would need an executive summary to be prepared for them to read quickly.
