Six Sigma In a Nutshell 郭倉義 中山大學 企管系. Six Sigma 不是 國王的新衣.
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Transcript of Six Sigma In a Nutshell 郭倉義 中山大學 企管系. Six Sigma 不是 國王的新衣.
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