---
id: wiki-2026-0508-bluf-bottom-line-up-front
title: BLUF (Bottom Line Up Front)
category: 10_Wiki/Topics
status: verified
canonical_id: self
aliases: [a1b2c3d4-e5f6-4901-2e3f-4a5b6c7d8e9f, Bottom Line Up Front]
duplicate_of: none
source_trust_level: A
confidence_score: 1.0
verification_status: applied
tags: [communication, writing, devops, incident-response]
raw_sources: []
last_reinforced: 2026-05-10
github_commit: pending
tech_stack:
  language: markdown
  framework: none
---

# BLUF (Bottom Line Up Front)

## 매 한 줄
> **"매 conclusion 을 첫 줄에 — recipient 가 더 못 읽어도 OK 하도록."**. US military origin 의 writing convention; 매 incident report, exec memo, PR description, on-call alert 의 표준 — 매 reader 의 cognitive load 를 minimize 하고 fastest decision-making 을 enable.

## 매 핵심

### 매 Structure
- **Line 1**: the conclusion / decision needed / status verdict.
- **Line 2-N**: supporting evidence in priority order.
- **Tail**: details, appendices, traces.

### 매 vs Narrative
- Narrative: "We started X, encountered Y, debugged Z, found root cause W, fixed it." — reader waits for punchline.
- BLUF: "Outage resolved. Root cause: misconfigured DNS. Restored 14:23 UTC." — punchline first.

### 매 응용
1. Incident postmortem TL;DR.
2. PR description first sentence.
3. Slack on-call escalation.
4. Email subject + first line.
5. Architecture decision record (ADR) summary.

## 💻 패턴

### Incident Slack Alert
```markdown
**[P1] Checkout API 5xx — DEGRADED**
Impact: 12% of orders failing since 14:05 UTC.
Action: rollback v2.4.1 in progress, ETA 5 min.
Owner: @oncall-payments
Thread: ↓
```

### Postmortem Top
```markdown
# Postmortem: 2026-05-08 Checkout Outage

**TL;DR**: 47-min P1 outage due to DNS TTL misconfig in v2.4.1 deploy.
- Customer impact: ~3,200 failed orders (~$84k revenue)
- Resolution: rollback at 14:23 UTC
- Action items: 4 (see §6)

## Timeline
...
```

### PR Description
```markdown
**Adds rate limiting to /api/checkout to prevent abuse.**

- New: `RateLimiter` middleware with Redis token bucket
- Default: 60 req/min per IP, configurable via env
- Tests: integration coverage for 429 path
- Risk: low — feature-flagged behind `RATE_LIMIT_ENABLED`

## Why
Spike on 05-06 saturated DB connections...
```

### Email Template
```markdown
Subject: [DECISION NEEDED by Fri] Migrate auth to OIDC — recommend Keycloak

Recommendation: adopt Keycloak for SSO; deprecate legacy LDAP by Q3.
Cost: $0 (OSS) + 2 SRE-weeks integration.
Risk: medium (auth migration); mitigated by phased rollout.

Background: ...
```

### ADR Header
```markdown
# ADR-0042: Use SQLite for local dev DB

**Decision**: SQLite for local; Postgres for staging/prod.
**Status**: accepted (2026-05-10)
**Context**: ... (3 paragraphs below)
```

### On-Call Status Page
```markdown
🟢 **All systems operational** — last incident 9 days ago.
Recent: deploys 4 (all green) · alerts 0 · SLO budget 99.4%
```

## 매 결정 기준
| 상황 | BLUF 적용 |
|---|---|
| Incident alert | YES — line 1 = severity + impact |
| Postmortem | YES — TL;DR block before timeline |
| Tutorial / explainer | NO — narrative 적합 |
| Marketing copy | NO — hook 후 reveal |
| ADR | YES — decision first |
| Bug report | YES — observed vs expected first |

**기본값**: ops/exec communication 은 BLUF; pedagogical/narrative 은 example-first.

## 🔗 Graph
- 부모: [[Technical Writing]]
- 응용: [[Postmortem]] · [[ADR]]
- Adjacent: [[Pyramid Principle]]

## 🤖 LLM 활용
**언제**: ask LLM to "rewrite as BLUF" — high-quality reflow.
**언제 X**: storytelling / customer-facing narrative.

## ❌ 안티패턴
- **Buried lede**: conclusion 을 §3 에 묻기.
- **Over-summarize**: line 1 이 vague ("there was an issue").
- **No context for novices**: BLUF 는 expert reader 가정 — onboarding doc 에는 부적합.
- **Decision-less BLUF**: "We did X" 보다 "Recommend Y" 가 actionable.

## 🧪 검증 / 중복
- Verified (US Army Field Manual, Google SRE Book postmortem chapter).
- 신뢰도 A.

## 🕓 Changelog
| 날짜 | 변경 |
|---|---|
| 2026-05-08 | Phase 1 |
| 2026-05-10 | Manual cleanup — full content with templates for incidents/PRs/ADRs |