The task
Month-end closed. You have an actuals-vs-plan table. The CFO wants variance commentary by 9am. You have 30 minutes and a copy of the file.
When this is the right job for AI
- You already have the variance table closed and reconciled — not still under revision.
- You can give AI just the variances and your top 1-2 known causes per line.
- You want narrative, not investigation. If you do not yet know why a line missed, AI cannot tell you.
What to feed the AI
- Variance table: line item, actual, plan, $ variance, % variance, favorable / unfavorable flag
- Materiality threshold (e.g. “explain only lines with |$ variance| > $200K or > 10%”)
- For each material line: one cause-hint you already know
- Audience and length
Copy-ready prompt
You are writing month-end variance commentary for the CFO.
Materiality: explain only variances > $200K OR > 10%.
Table:
| Line | Actual | Plan | Var $ | Var % | F/U | Known cause hint |
| Revenue | 12.4M | 12.0M | +400K | +3.3% | F | Enterprise renewal closed 2 weeks early |
| Gross margin | 56.2% | 58% | -180bps | - | U | Input costs up; freight |
| Sales OpEx | 2.8M | 2.5M | +300K | +12% | U | Two open reqs filled |
| Marketing OpEx | 0.9M | 1.2M | -300K | -25% | F | Q3 campaign delayed |
| R&D | 1.8M | 1.8M | 0 | 0 | - | - |
Write:
1. One headline: net P&L impact and the single most important explanation.
2. One bullet per material line: variance, root cause in plain English, whether it is structural or one-time, and whether to expect recurrence.
3. One "watch this" — the variance with the most uncertain cause.
200 words. No raw percentages a non-finance reader cannot see.
Sample output structure
Headline: P&L net favorable +$220K, driven by Q3 marketing campaign push-out — operating leverage was timing, not improvement.
- Revenue +$400K favorable: enterprise renewal closed two weeks early. One-time — do not assume in Q4.
- Gross margin -180bps unfavorable: input costs and freight. Structural — expect to persist absent supplier renegotiation.
- Sales OpEx +$300K unfavorable: two open reqs filled mid-month. Structural going forward — full quarter run rate in Q4.
- Marketing OpEx -$300K favorable: Q3 campaign pushed to Q4. One-time — full spend lands in Q4.
Watch this: gross margin. If input costs hold, Q4 margin lands closer to 55% than plan’s 58%.
How to refine
- AI labels everything “structural” — push back: “Most variances are one-time at month level. Default to one-time unless I told you otherwise.”
- Commentary too soft (“could be a concern”) — add “use direct language; the CFO has seen one-month noise before.”
- AI invents causes for lines where you gave no hint — strict rule: “if I gave no cause hint for a line, mark it
cause unknown - in progressand move on.”
Common mistakes
- Pasting the full GL trial balance. AI will explain noise.
- Forgetting the materiality threshold — the commentary becomes line-item noise, not analysis.
- Letting AI mix favorable and unfavorable in the same bullet. Separate them; favorable variances need scrutiny too.
- Sending the commentary without checking the math. AI will sometimes restate $ variances slightly off — always verify the headline number.
Practical depth notes
For AI Variance Analysis: From Actuals-vs-Plan to a One-Page Explanation, the difference between a usable AI result and a generic one is the input packet. Give the model the audience, the current draft or raw material, the desired format, the decision you need to make, and two examples of what good and bad output look like. Ask it to preserve facts first, then improve structure or wording second.
After the first response, do a separate review pass. Look for missing constraints, invented details, weak calls to action, and language that sounds plausible but does not match the real situation. The best final output should be easy to use immediately: clear owner, clear next step, and no hidden assumption that someone else has to untangle. A stronger version of this workflow also defines the handoff. Decide who will use the output, what they should do next, and what information would make them reject it. If the deliverable is copy, test whether it has a single clear action. If it is analysis, test whether it separates observation from recommendation. If it is planning, test whether dates, owners, and tradeoffs are explicit enough for someone else to execute. One final check: compare the finished result against the original goal in a single sentence. If that sentence is hard to write, the output is probably polished but unfocused. Tighten the goal, remove decorative language, and rerun only the weak section instead of regenerating the entire piece.
FAQ
- What about budget vs forecast vs actuals? Same template — replace “plan” with “forecast” in the prompt. The structural/one-time framing is identical.
- Can I share the table with ChatGPT? Use a corp-approved enterprise tenant. Strip the legal entity name if your policy is strict.
- How is this different from business driver analysis? Drivers explain why a metric moved. Variance explains why it missed plan. Same data, different lens.
Related
- AI business driver breakdown
- AI financial trend analysis
- AI KPI weekly report
- AI executive summary
- Excel / Spreadsheet Analysis Prompts
Tags: #AI writing #Finance #Business analysis #KPI #Executive update