An executive summary is a report, proposal, or portfolio, etc in miniature (usually one page or shorter). That is, the executive summary contains enough information for the readers to become acquainted with the full document without reading it. Usually, it contains a statement of the problem, some background information, a description of any alternatives, and the major conclusions. Someone reading an executive summary should get a good idea of main points of the document without becoming bogged down with details.

 An executive summary differs from an abstract in that an abstract is usually only about six to eight lines long. Its purpose is to inform the reader of the points to be covered in the report without any attempt to tell what is said about them. Covering no more than a page in length, the executive summary is longer and is a highly condensed version of the most important information the full document contains. Both the executive summary and the abstract are independent elements rather than a part of the body of the document. Both are placed at the beginning of the document.

 With the possible exception of the conclusion and recommendation, the executive summary is the most important part of a report. As such, it should be the best-written and most polished piece of the document. This is because many readers may only look at the executive summary when deciding whether or not to read the entire document. In some companies, the executive summaries are distributed so that employees are informed as to what information is available, and interested readers may request the entire document. In short, you may expect that an executive summary will be read more frequently and by more people than will your entire document.

When writing your executive summary, ask yourself if those who read the summary will be those who will read the entire report. If you are dealing with two different groups of people, you will have to decide how much technical detail to include in the summary. If it is likely that some who read only the executive summary will not have the technical background of the writer or final reader, keep the technical information and vocabulary to a minimum. You might have three types of readers: those who want a full picture but won't check the details (they might read the executive summary, some of the body, the conclusions, and the recommendations), those who read everything (they read the appendices, all the data, the calculations, etc.), and those who are in executive positions, wish to be kept informed on what is going on in the company, and will say "yes" or "no" to a project (they will read the executive summary, the conclusions, and the recommendations). Your executive summary must address all three types of readers.

Since the executive summary is a condensation, when creating it, you omit any preliminaries, details, and illustrative examples. You do include the main ideas, the facts, the necessary background to understand the problem, the alternatives, and the major conclusions. Brevity and conciseness are the keys to a well-written summary. Do not take a few sentences from key sections of the document and string them together. Rather, go over the entire document and make notes of the elements you consider important. From your notes, create a rough draft of the summary. Then, polish what you have written until it is smooth and seamless without unnecessary wordiness. Do not include any introductory or transitional material. Finally, ensure that your executive summary is accurate and representative of your full document. It should not be misleading, but it should give readers the same impression as if they had read the entire report.