biz-lean-six-sigma
用精實與六標準差消除浪費、降低流程變異
中文翻譯
---
name: "biz-lean-six-sigma"
description: "套用精實（Lean）與六標準差（Six Sigma）原則，消除浪費並降低流程變異。當使用者需要提升營運效率、找出七大浪費（TIMWOOD）、執行 DMAIC 改善專案、或精簡工作流程時使用，即使他們說的是「我們的流程太慢了」、「我們在哪裡浪費資源」或「怎麼減少瑕疵」也一樣。"
metadata:
category: "WP-16 商學院—營運"
tags: ["operations", "lean", "six-sigma", "process-improvement"]
---
# 精實六標準差（Lean Six Sigma）
## 概述
精實消除浪費（沒有增加價值的活動）。六標準差降低變異（瑕疵和不一致）。兩者結合，同時改善速度「和」品質。精實回答「我們是不是在做不必要的事？」六標準差回答「我們有沒有一致地做好必要的事？」
## 框架
```
鐵律：價值是由「顧客」定義的，不是由生產者
一項活動只有在下列條件都成立時才增加價值：(1) 顧客願意為它付錢，
(2) 它轉變了產品／服務，而且 (3) 第一次就做對。
只要有任何一個條件不成立，這項活動就是浪費，要消除或降到最低。
```
### 七大浪費（TIMWOOD）
| 浪費 | 定義 | 範例 |
|-------|-----------|---------|
| **T**ransportation（運輸） | 不必要的物料移動 | 在倉庫之間搬移庫存 |
| **I**nventory（庫存） | 超出當下所需的多餘存貨 | 閒置了 6 個月的原料 |
| **M**otion（動作） | 人員不必要的移動 | 走過整個廠區去拿工具 |
| **W**aiting（等待） | 流程步驟之間的閒置時間 | 訂單在等待核准 |
| **O**ver-production（過度生產） | 做得比需要的多 | 只有 100 份會被讀，卻印了 1000 份報告 |
| **O**ver-processing（過度加工） | 做得比顧客要求的更多 | 對非關鍵的表單檢查三遍 |
| **D**efects（瑕疵） | 需要重工或報廢的產出 | 軟體 bug、製造的不良品 |
### DMAIC 改善循環（六標準差）
1. **Define（定義）**：問題是什麼？顧客是誰？目標指標是什麼？
2. **Measure（衡量）**：目前的績效如何？蒐集瑕疵率、週期時間、變異的資料。
3. **Analyze（分析）**：是什麼造成這個問題？使用根本原因分析（5 Whys、魚骨圖、柏拉圖）。
4. **Improve（改善）**：什麼改變能解決它？設計並測試解決方案。
5. **Control（控制）**：如何維持改善成果？落實監控、SOP、管制圖。
### Kaizen（持續改善）
由第一線員工持續進行的小幅、漸進式改善：
- 每日站會找出一項改善
- 可以的話立即實施
- 記錄並在團隊間分享
## 輸出格式
```markdown
# 精實六標準差分析：{流程}
## 現況
- 流程：{描述}
- 關鍵指標：{瑕疵率 / 週期時間 / 成本}
- 目前績效：{基準資料}
## 浪費辨識（TIMWOOD）
| 浪費類型 | 有發現？ | 描述 | 影響 |
|-----------|--------|-------------|--------|
| 運輸 | Y/N | {細節} | 高/中/低 |
| 庫存 | Y/N | ... | ... |
| 動作 | Y/N | ... | ... |
| 等待 | Y/N | ... | ... |
| 過度生產 | Y/N | ... | ... |
| 過度加工 | Y/N | ... | ... |
| 瑕疵 | Y/N | ... | ... |
## 根本原因分析
{針對最主要浪費的 5 Whys 或魚骨圖}
## 改善計畫（DMAIC）
| 階段 | 行動 | 負責人 | 時程 |
|-------|--------|-------|----------|
| 定義 | {問題陳述} | ... | ... |
| 衡量 | {資料蒐集計畫} | ... | ... |
| 分析 | {根本原因的方法} | ... | ... |
| 改善 | {解決方案} | ... | ... |
| 控制 | {監控計畫} | ... | ... |
## 預期影響
- {指標}：{目前} → {目標}（改善 {X%}）
```
## 範例
### 正確的應用
**情境：** 對餐廳廚房訂單流程的精實分析
- **等待浪費**：訂單要等 8 分鐘，才被出餐員彙整批次 → 改成即時的票單系統（每張訂單省 6 分鐘）
- **動作浪費**：廚師每張訂單要走 15 公尺到冷藏庫 → 把備料站的冰箱搬位置（省 2 分鐘）
- **瑕疵浪費**：12% 的訂單錯誤率 → 導入有視覺確認的廚房顯示系統（目標 3%）
- 根本原因（5 Whys）：出錯 → 手寫票單 → 字跡不清 → 沒有標準化格式 → **沒有數位點餐系統**
### 錯誤的應用
- 把「市場正在衰退」認定為一種浪費 → 市場狀況是外部的，不是流程浪費。TIMWOOD 只適用於內部流程。
## 常見陷阱
- **第 8 種浪費：未被運用的人才**：常被加進 TIMWOOD。員工的想法沒被聽見，或技能沒被運用。
- **精實也可能過頭**：消除「所有」庫存（零緩衝）會造成脆弱。有些「浪費」是策略性的緩衝。要在效率與韌性之間取得平衡。
- **六標準差需要資料**：沒有基準衡量，就算不出改善幅度。在跳到解決方案之前，先投資在衡量上。
- **文化上的抗拒**：精實／六標準差需要第一線的認同。沒有員工參與的由上而下指令會失敗。
## 參考資料
- 價值流程圖的方法，見 `references/value-stream-mapping.md`
- 統計製程管制（SPC），見 `references/spc-basics.md`英文原文
---
name: "biz-lean-six-sigma"
description: "Apply Lean and Six Sigma principles to eliminate waste and reduce process variation. Use this skill when the user needs to improve operational efficiency, identify the seven wastes (TIMWOOD), run DMAIC improvement projects, or streamline workflows — even if they say 'our process is too slow', 'where are we wasting resources', or 'how do we reduce defects'."
metadata:
category: "WP-16 商學院—營運"
tags: ["operations", "lean", "six-sigma", "process-improvement"]
---
# Lean Six Sigma
## Overview
Lean eliminates waste (non-value-adding activities). Six Sigma reduces variation (defects and inconsistency). Combined, they improve speed AND quality. Lean answers "are we doing unnecessary things?" Six Sigma answers "are we doing necessary things consistently?"
## Framework
```
IRON LAW: Value Is Defined by the CUSTOMER, Not the Producer
An activity adds value ONLY if: (1) the customer is willing to pay for it,
(2) it transforms the product/service, AND (3) it's done right the first time.
If any condition fails, the activity is waste — eliminate or minimize it.
```
### The Seven Wastes (TIMWOOD)
| Waste | Definition | Example |
|-------|-----------|---------|
| **T**ransportation | Unnecessary movement of materials | Moving inventory between warehouses |
| **I**nventory | Excess stock beyond immediate need | 6 months of raw materials sitting idle |
| **M**otion | Unnecessary movement of people | Walking across factory floor to get tools |
| **W**aiting | Idle time between process steps | Orders waiting for approval |
| **O**ver-production | Making more than needed | Printing 1000 reports when 100 are read |
| **O**ver-processing | More work than the customer requires | Triple-checking a non-critical form |
| **D**efects | Output that requires rework or disposal | Software bugs, manufacturing rejects |
### DMAIC Improvement Cycle (Six Sigma)
1. **Define**: What is the problem? Who is the customer? What is the target metric?
2. **Measure**: What is the current performance? Collect data on defect rate, cycle time, variation.
3. **Analyze**: What causes the problem? Use root cause analysis (5 Whys, fishbone diagram, Pareto chart).
4. **Improve**: What changes will fix it? Design and test solutions.
5. **Control**: How to sustain the improvement? Implement monitoring, SOPs, control charts.
### Kaizen (Continuous Improvement)
Small, incremental improvements made continuously by frontline workers:
- Daily standup to identify one improvement
- Implement immediately if possible
- Document and share across teams
## Output Format
```markdown
# Lean Six Sigma Analysis: {Process}
## Current State
- Process: {description}
- Key metric: {defect rate / cycle time / cost}
- Current performance: {baseline data}
## Waste Identification (TIMWOOD)
| Waste Type | Found? | Description | Impact |
|-----------|--------|-------------|--------|
| Transportation | Y/N | {detail} | H/M/L |
| Inventory | Y/N | ... | ... |
| Motion | Y/N | ... | ... |
| Waiting | Y/N | ... | ... |
| Over-production | Y/N | ... | ... |
| Over-processing | Y/N | ... | ... |
| Defects | Y/N | ... | ... |
## Root Cause Analysis
{5 Whys or fishbone diagram for top waste}
## Improvement Plan (DMAIC)
| Phase | Action | Owner | Timeline |
|-------|--------|-------|----------|
| Define | {problem statement} | ... | ... |
| Measure | {data collection plan} | ... | ... |
| Analyze | {root cause method} | ... | ... |
| Improve | {solution} | ... | ... |
| Control | {monitoring plan} | ... | ... |
## Expected Impact
- {metric}: {current} → {target} ({X% improvement})
```
## Examples
### Correct Application
**Scenario:** Lean analysis of a restaurant kitchen order process
- **Waiting waste**: Orders wait 8 min for expeditor to batch them → Change to real-time ticket system (saves 6 min/order)
- **Motion waste**: Chef walks 15m to reach cold storage per order → Relocate prep station fridge (saves 2 min)
- **Defect waste**: 12% order error rate → Implement kitchen display system with visual confirmation (target 3%)
- Root cause (5 Whys): Errors → handwritten tickets �� poor handwriting → no standardized format �� **no digital order system**
### Incorrect Application
- Identified "the market is declining" as a waste → Market conditions are external, not process waste. TIMWOOD applies to internal processes only.
## Gotchas
- **8th waste — unused talent**: Often added to TIMWOOD. Employees with ideas that aren't heard or skills that aren't utilized.
- **Lean can go too far**: Eliminating ALL inventory (zero buffer) creates fragility. Some "waste" is strategic buffer. Balance efficiency with resilience.
- **Six Sigma requires data**: Without baseline measurements, you can't calculate improvement. Invest in measurement before jumping to solutions.
- **Cultural resistance**: Lean/Six Sigma requires frontline buy-in. Top-down mandates without worker involvement fail.
## References
- For value stream mapping methodology, see `references/value-stream-mapping.md`
- For statistical process control (SPC), see `references/spc-basics.md`