| name | pareto-principle |
| description | Isolate the 20% of inputs driving 80% of results, and explicitly name what you're deprioritizing. Outputs a blockquote (vital 20%) plus a list (deprioritized 80%). Use for ruthless prioritization, "what should we focus on", or step 4 of a strategic analysis. |
Pareto Principle (80/20)
Concept
In most systems, ~80% of the outcome comes from ~20% of the inputs. Strategy consultants use this constantly: figure out which 20% of customers, products, channels, or root causes drive the lion's share of impact, and ignore the rest until later.
The discipline isn't naming the vital 20%. It's having the spine to explicitly deprioritize the 80%. If everything is important, nothing is.
Required output format
Two parts, in this order:
- A Markdown blockquote naming the vital 20%.
- A bulleted list under "Actively deprioritized (the 80%):" naming what's being set aside.
> **The vital 20%:** [Specific factors/segments/causes that drive the majority of impact.]
**Actively deprioritized (the 80%):**
- Item 1
- Item 2
Defaults & flex points
| Default | When to flex |
|---|
| 1–4 items in the vital 20% | If the 80/20 genuinely points to one thing, use one. Don't pad. |
| 5–10 items in the deprioritized list | List enough to make the deprioritization visible — but if there are only 3 real alternatives, list 3. |
| Specificity in the vital 20% | Don't flex — "our top customers" is too vague. Name them. |
| Explicit deprioritization | Don't flex — implicit deprioritization is no deprioritization. |
The hardest discipline: writing down something that genuinely matters into the deprioritized list. If your 80% list is full of things that don't matter, you haven't really prioritized. Real Pareto says: "Yes, X matters. We're not doing X this quarter."
Example — engineering tech debt
Problem: A mid-stage SaaS engineering team has 47 tracked tech-debt items. Leadership wants a focused six-month plan.
The vital 20%: Three items account for ~80% of incident pain and velocity drag: (1) the legacy auth middleware causing 60% of P2 tickets and forcing every new feature to add custom session handling, (2) the deploy pipeline averaging 47 minutes (preventing the team's stated daily-deploy cadence), and (3) the absence of integration tests on the billing module (the source of 4 of the last 6 customer-impacting incidents).
Actively deprioritized (the 80%):
- Migrating the frontend from React 17 to React 18 (real, but no business pull)
- Refactoring the admin dashboard (technically owed but low-traffic surface)
- Rewriting the email templating system (works fine, just ugly)
- Splitting the monolith into services (premature for current scale)
- Upgrading the logging library (operational only, no incidents tied to it)
- Switching ORMs (engineer preference, not business need)
- Modernizing the build tool (current setup works, savings minimal)
Notice: several deprioritized items are real concerns. The point is naming them as not-this-half so the team has cover to focus.
Common mistakes
- The "everything is 20%" cop-out. A list of 12 priorities labeled "vital 20%" is just a backlog with extra steps.
- Implicit deprioritization. Mentally noting what you're not doing isn't the same as writing it down. Stakeholders will assume you're doing everything.
- Soft language. "We could consider focusing on..." dilutes the point. The blockquote is a commitment.
- Deprioritizing trivial things. If everything in your 80% list is obvious filler, the framework isn't biting.
When to use this skill alone vs. as part of the full analysis
- Standalone: when the user has a long list of options and needs to commit to a few.
- As part of full analysis:
strategy-consultant — Pareto is step 4 of 5. Run mece-framework and issue-trees first to enumerate the 100% before you can isolate the 20%.
Acknowledgment & License
Adapted from Analyst Academy on YouTube — 5 Consulting Frameworks to Solve Any Problem. MIT-licensed; see LICENSE.
