Most executive summaries fail on the same six mistakes: buzzwords instead of figures, too much background, contradictions with the main document, new topics, jargon and a missing decision. For each mistake you find the fix here, plus a before-and-after example. What an executive summary is and how to structure one is covered in our article How to write an executive summary: format, example and free template.
Which Mistakes Make an Executive Summary Weak?
Six mistakes show up in executive summaries again and again. The table lists them with their fix; the sections below explain each one.
| Mistake | Fix |
|---|---|
| 1. Buzzwords instead of figures | Replace every judgment with the figure behind it |
| 2. Too much background | Keep only what supports the decision |
| 3. Contradictions with the main document | Check figures and terms last |
| 4. New topics the main text does not cover | Summarize only what the document explains |
| 5. Jargon for non-specialist readers | Write in the decision maker's language |
| 6. No conclusion, no decision | End with recommendation, deadline and cost |
Mistake 1: Buzzwords Instead of Figures
Sentences such as "The project is progressing excellently" or "enormous market potential" give the reader nothing to work with. If you do not back such judgments with market research, project data or customer statements, you lose credibility, and the reader draws their own conclusions.
Fix: Replace every judgment with the figure it rests on. Instead of "well within budget", write "44 percent of the budget spent at 46 percent completion".
Mistake 2: Too Much Background
History, methodology and market details push the key message aside. The reader has to search for what you want from them and, in doubt, stops reading first.
Fix: Test every sentence with one question: does the reader need it for the decision? Everything else stays in the main document. How long an executive summary may be is covered in our executive summary guide.
Mistake 3: Contradictions With the Main Document
If the summary states €2.1 million in costs and page 12 of the report says €2.3 million, the reader trusts neither figure. The same applies to terms: if the dates are called "milestones" at the front and "project goals" at the back, the reader looks for two different things.
Fix: Write the summary last and check every figure and every term against the main document. Take dates and percent complete directly from the project plan, not from a side calculation.
Mistake 4: New Topics the Main Text Does Not Cover
The summary summarizes; it does not introduce topics of its own. If it mentions a solution, a risk or a figure that the document does not explain, the reader cannot verify the statement.
Fix: Every topic in the summary needs a section in the main document. If that section is missing, add it or remove the topic from the summary.
Mistake 5: Jargon for Non-Specialist Readers
Decision makers often come from a different discipline. A CFO does not need to know what additional foundation work is; they need to know what it costs and whether the date holds.
Fix: Write so that a non-specialist understands the text. Explain unavoidable technical terms in half a sentence and keep the tone of the rest of the document.
Mistake 6: No Conclusion, No Decision
Many summaries end with "Further details can be found in the report." The reader then knows what happened, but not what to do. Check your ending with three questions:
- Does the reader understand which solution you propose?
- Do they see the problem this solution addresses?
- Can they decide based on the summary alone?
Fix: End the summary with your recommendation, the deadline and the cost.
Example: The Same Executive Summary Before and After
Both versions describe the same status of a fictitious new office building. The first makes mistakes 1, 2 and 6; the second fixes them.
Before
Since breaking ground in spring, the Hafenstraße project has made impressive progress. After intensive consultations with the soil expert and several site visits, the team has mastered the challenges at axis C. We are confident that we will reach our ambitious goals. Further details can be found in the report.
After
The structural shell is complete, two weeks later than planned. Handover on 30 Jun 2027 remains achievable if you approve six Saturday shifts for the facade by 9 Oct 2026. They cost €38,400; the risk reserve covers them, and the budget of €4,800,000 stays unchanged.
What changed:
- Figures instead of judgments: "impressive progress" becomes status, delay and cost (mistake 1).
- No background: breaking ground, the soil expert and site visits stay in the report, not in the summary (mistake 2).
- A decision with a deadline: the reader knows what to approve by when and what it costs (mistake 6).
You find the complete executive summary of this status report with all parts in our article How to write an executive summary: format, example and free template.
What Should Not Be Included in an Executive Summary?
An executive summary should not include details the reader does not need for the decision. In particular:
- Extensive background and methodology: approach, research design and history belong in the main text.
- Raw data and long tables: the summary names three to five key figures; detailed data belongs in the appendix.
- Bibliography and long citations: full references belong in the main document.
- New topics that the main document does not explain (mistake 4).
- Personal opinions and anecdotes that do not support the recommendation.
Should an Executive Summary Have References?
Usually not: full references and citations belong in the main document. If your recommendation rests on a single external figure, such as a market size, name the publisher and year in brackets right after it. The reader can then place the figure without the summary getting longer.
Does an Executive Summary Include Risks?
Yes, if they affect the recommendation. Name the two or three risks that threaten the schedule, budget or goal, each with the planned mitigation in one sentence. The full risk analysis stays in the main document.
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