Six Sigma In a Nutshell

郭倉義中山大學 企管系

Six Sigma

不是

國王的新衣

另一個『三字經』：六標準差• 6• TQM• SPC• SQC• QCC

• SCM• CRM• ERP• BPR

Six Sigma

是

專案跨部門

Powerful process improvement tools

• Six Sigma– Save General Electric $1.5 billion in 1999– Increase the market value of AlliedSignal by

700%– Boosted sales by more than 300% at Motorola

www.traininguniversity.com, 2000, “Training for Excellence”

• GE’s annual report 1999– Revenues rose 11% to $112 billion– Earnings increased 15% to $10.7 billion– Made 134 acquisitions, worth almost $17

billion

Six Sigma moment passed?

• Robert Nardelli– CEO, Home Depot

• Six Sigma were used– streamline the check-out process– strategically place vacuum-cleaner displays

• Results– constant data measurement and paperwork sapped time

given to customers» Profitability soared, » 員工士氣低落 , » 顧客抱怨

Six Sigma: So Yesterday? JUNE 11, 2007, Business Week

• Jeff Immelt– CEO, GE

• reprogram his management ranks to innovate

• James McNerney– CEO, 3M

• axed 8,000 workers (about 11% of the workforce)• intensified the performance-review process

– his successors• relentless emphasis on efficiency had made 3M a l

ess creative company (?)

• Six Sigma 真的沒用嘛– 可能是『沒用對地方』

» 用 Six Sigma 去解決不重要的問題 – 假議題

– 對付腸病毒，「乾洗手」沒效 • 「乾洗手」的成分是酒精• 酒精會溶解『病毒』的「脂質外套膜」，殺死病毒 • 『腸病毒』沒有外套膜

– 酒精對腸病毒是無效的– 『漂白水』可以使蛋白質變性，進而殺死腸病毒

Six Sigma

目標兩年成長 10 倍

The six sigma rate of improvement goal

is

a ten-fold improvement every two years

Six Sigma

不只是

DMAICDefine-Measurement-Analysis-Improvement-Control

六標準差的失敗

不是六標準差的錯

是變革管理的錯

Change Managementfor transition to six sigma

vision Skills Incentive Resources Action plan Change+ + + + =

Skills Incentive Resources Action plan Confusion+ + + =

vision Incentive Resources Action plan Anxiety+ + + =

vision Skills Resources Action plan GraduateChange

+ + + =

vision Skills Incentive Action plan Frustration+ + + =

vision Skills Incentive Resources FalseStarts

+ + + =

How important is

Six Sigma

“Within senior management incentive plans,

A minimum of 30 percent of their bonus potential should be dependent on

achieving quality goals.”

Demystifying Six Sigma

A company-wide approach to continuous improvement

Alan Larson

Six Sigma at a Glance

• Alan Larson– One of the original divisional quality directors

at Motorola• Developing• Training• Deploying

the culture and methods of Six Sigma

– Achievement• Reduce cost

– Cost of sales by 30 percent

• Improve efficiencies– Cycle time and cost of administration and service by 90

percent

• Maximize customer satisfaction

in all operations at Motorola

Why Six Sigma had to be invented

• In the mid-1980s– Motorola was losing ground to its Japanese

competitors– Customer’s comments

• “Love, love, love the product; hate, hate, hate the company”

– Motorola’s systems for doing business– Contract review– Response to requests for quote– Response to customer complaints– ……

• Were not designed for customer satisfaction• The internal bureaucracy fed on itself

– Motorola’s product suffers• Too many out-of-box failures• High level of early-life failure

– Warranty returns– Were predominately units that

» Had failed at final test» Had gone through a rework cycle

– Motorola’s reaction• Benchmark those Japanese companies that were

destroying Motorola– Senior managers and executives sent on a

benchmarking tour of Japan» Operating methods» Product quality method

• Discovered– National program for employee involvement

» Use employee’s muscle and their brains and knowledge

The Birth of Six Sigma

• Motorola learned– From customers

• Need to change all systems to focus on total customer satisfaction

– From Japanese• Involvement all employees to increase efficiency

and moral• Simpler designs result higher levels of quality and

reliability

– From early-life field failure study• Products need to be built right the first time

• Motorola’s leader pulled this together to – establish vision and – set the framework for– six sigma

• Six Sigma was launched in 1987

Mathematics of Six Sigma

• Opportunities-for-error• DPMO: defect per million opportunity

• A way of leveling the playing field– Manufacturing operations vs order-entry work

• Account for differing complexities– An invoice consisting of 40 line items vs 2 line

items

Different numbers of Opportunities ...

Manufacturing Processes

Customers or Suppliers

Administrative Areas

6

• Sigma calculations are controversial– Attribute data

– Go, no-go

• Utilizing normal curve and z-table violates many of the rules of statistics

– Accounting for variation over time by adding 1.5 sigma to the actual z-table

Sigma calculations are developed empirically

A Bit of Statistics ...

-7.0

-6.0

-5.0

-4.0

-3.0

-2.0

-1.0 0.

0 1.0

2.0

3.0

4.0

5.0 6.0

7.0

upper spec limitLower spec limit

+1.5 Sigma-1.5 Sigma

3.4 ppm

or Zero

+

• Sigma-scale measures– Optional element of six sigma system

The six sigma way – Pande, et al.

良率 DPMO Sigma

6.68 93320 0

六標準差轉換表 標準常態分配表

Black belts and Green belts

• Local statistical resources (LSR)– Engineers trained in advanced form

• Experimental design• Data analysis• Process control

Black belt

• Total customer satisfaction (TCS) team– Factory workers– Received training and couching in problem-

solving methods

Green belt

• “Black belts” and “Green belts” were not applied to six sigma program at Motorola until the 1990s

• Avoid special-assignment employee with the title of “Black Belt”– External to the operations that they support

• Expensive• Less-than-optimum structure for six sigma

– Disenfranchise most employee– Convenient way for employee to abandon their

responsibility

– Only result in short term benefits