mfg-oee-analysis

Compare original and translation side by side

🇺🇸

Original

English

🇨🇳

Translation

Chinese

OEE Analysis

OEE分析

Framework

框架

IRON LAW: OEE = Availability × Performance × Quality

OEE is a MULTIPLICATIVE metric. 90% × 90% × 90% = 72.9%, not 90%.
Each factor compounds the loss. World-class OEE is 85%+. Most plants
operate at 60-65%. Knowing the TOTAL is useless — you must decompose
to find which factor is dragging performance down.

IRON LAW: OEE = Availability × Performance × Quality

OEE is a MULTIPLICATIVE metric. 90% × 90% × 90% = 72.9%, not 90%.
Each factor compounds the loss. World-class OEE is 85%+. Most plants
operate at 60-65%. Knowing the TOTAL is useless — you must decompose
to find which factor is dragging performance down.

The Three Factors

三大核心因素

Factor	Formula	Measures	Loss Categories
Availability	Run Time / Planned Production Time	Uptime vs downtime	Equipment failures, changeovers, material shortages
Performance	(Ideal Cycle Time × Total Count) / Run Time	Actual speed vs design speed	Minor stops, slow running, idling
Quality	Good Count / Total Count	Yield, first-pass quality	Defects, rework, scrap, startup rejects

因素	公式	衡量指标	损失类别
Availability	运行时间 / 计划生产时间	运行时间 vs 停机时间	设备故障、换产、物料短缺
Performance	(理想周期时间 × 总产量) / 运行时间	实际速度 vs 设计速度	小幅停机、低速运行、空转
Quality	合格产量 / 总产量	良率、一次合格率	次品、返工、报废、启动阶段废品

Six Big Losses (mapped to OEE factors)

六大损失（对应OEE因素）

Loss	OEE Factor	Example
1. Equipment failure	Availability	Machine breakdown, unplanned repair
2. Setup & changeover	Availability	Product changeover, die change, cleaning
3. Idling & minor stops	Performance	Sensor blockage, jam clearing, small adjustments
4. Reduced speed	Performance	Running below rated speed due to wear or material
5. Process defects	Quality	In-process rejects, rework
6. Startup rejects	Quality	Scrap during warm-up, first-article failures

损失类型	OEE因素	示例
1. 设备故障	Availability	机器故障、非计划性维修
2. 换产与调试	Availability	产品切换、模具更换、设备清洁
3. 空转与小幅停机	Performance	传感器堵塞、卡料清理、小幅调整
4. 速度损失	Performance	因设备磨损或物料问题导致低于额定速度运行
5. 制程次品	Quality	制程内废品、返工
6. 启动阶段废品	Quality	预热阶段报废、首件不合格

Calculation Example

计算示例

Planned Production Time: 480 min (8-hour shift)
Downtime (breakdowns + changeover): 60 min
Run Time: 420 min

Ideal Cycle Time: 1 min/unit
Total Units Produced: 380

Good Units: 360
Defective Units: 20

Availability = 420 / 480 = 87.5%
Performance = (1 × 380) / 420 = 90.5%
Quality = 360 / 380 = 94.7%

OEE = 87.5% × 90.5% × 94.7% = 75.0%

Planned Production Time: 480 min (8-hour shift)
Downtime (breakdowns + changeover): 60 min
Run Time: 420 min

Ideal Cycle Time: 1 min/unit
Total Units Produced: 380

Good Units: 360
Defective Units: 20

Availability = 420 / 480 = 87.5%
Performance = (1 × 380) / 420 = 90.5%
Quality = 360 / 380 = 94.7%

OEE = 87.5% × 90.5% × 94.7% = 75.0%

Diagnosis Steps

诊断步骤

Phase 1: Calculate OEE for each production line/machine Phase 2: Identify the weakest factor (Availability, Performance, or Quality) Phase 3: Pareto the losses within that factor (which specific loss is biggest?) Phase 4: Root cause analysis on the top loss (5 Whys, fishbone) Phase 5: Improve and remeasure

阶段1： 计算每条生产线/每台设备的OEE 阶段2： 识别最弱的核心因素（可用率、性能率或合格率） 阶段3： 对该因素下的损失进行帕累托分析（哪项具体损失占比最大？） 阶段4： 对主要损失进行根本原因分析（5Why法、鱼骨图） 阶段5： 实施改进并重新测量

Benchmarks

基准参考

OEE Level	Rating	Typical
> 85%	World-class	Top manufacturers
60-85%	Typical	Room for improvement
40-60%	Low	Significant losses, urgent action needed
< 40%	Critical	Equipment or process fundamentally broken

OEE水平	评级	典型场景
> 85%	世界级	顶尖制造企业
60-85%	常规水平	存在改进空间
40-60%	较低水平	损失严重，需紧急处理
< 40%	危急水平	设备或制程存在根本性问题

Output Format

输出格式

markdown

undefined

markdown

undefined

OEE Report: {Production Line}

OEE Summary

Factor	Value	Benchmark	Status
Availability	{%}	>90%	🟢/🟡/🔴
Performance	{%}	>95%	🟢/🟡/🔴
Quality	{%}	>99%	🟢/🟡/🔴
OEE	{%}	>85%	🟢/🟡/🔴

Factor	Value	Benchmark	Status
Availability	{%}	>90%	🟢/🟡/🔴
Performance	{%}	>95%	🟢/🟡/🔴
Quality	{%}	>99%	🟢/🟡/🔴
OEE	{%}	>85%	🟢/🟡/🔴

Loss Breakdown

Loss	Minutes Lost	% of Total Loss	Priority
{loss type}	{min}	{%}	1/2/3

Loss	Minutes Lost	% of Total Loss	Priority
{loss type}	{min}	{%}	1/2/3

Root Cause (Top Loss)

{5 Whys or fishbone analysis}

Improvement Plan

Action	Target Impact	Timeline	Owner
{action}	+{X%} OEE	{weeks}	{who}

undefined

Action	Target Impact	Timeline	Owner
{action}	+{X%} OEE	{weeks}	{who}

undefined

Gotchas

注意事项

OEE is per machine, not per plant: Plant-level OEE averages hide that one machine at 95% and another at 45% average to 70%. Analyze individually.
Planned downtime is excluded: OEE measures losses against PLANNED production time. Scheduled maintenance, no-production shifts, and planned shutdowns are excluded from the denominator.
100% OEE is not the goal: It would mean zero changeovers, zero defects, running at max speed 100% of the time. Pursuing 100% can increase costs (e.g., never doing preventive maintenance). Target 85%+ for critical lines.
Data collection is the real challenge: Manual OEE tracking is inaccurate. Invest in automated data collection (sensors, MES integration) for reliable measurement.

OEE是单台设备的指标，而非工厂级指标：工厂级OEE平均值会掩盖“一台设备OEE为95%、另一台为45%，最终平均为70%”的真实情况，应单独分析每台设备。
计划停机时间需排除在外：OEE是针对计划生产时间计算损失的指标。预防性维护、无生产班次、计划停机等均不计入分母。
100% OEE并非目标：这意味着零换产、零次品、全程满速运行。追求100%可能增加成本（如从不进行预防性维护），关键生产线目标应设为85%以上。
数据采集是核心挑战：手动跟踪OEE准确性低，应投资自动化数据采集方案（传感器、MES系统集成）以获得可靠数据。

References

参考资料

For TPM (Total Productive Maintenance) methodology, see
```
references/tpm.md
```
For automated OEE data collection, see
```
references/oee-automation.md
```

关于全面生产维护（TPM）方法论，请参阅
```
references/tpm.md
```
关于自动化OEE数据采集，请参阅
```
references/oee-automation.md
```