Six Sigma is a business management strategy, originally developed by Motorola, that today enjoys wide-spread application in many sectors of industry.
Six Sigma seeks to identify and remove the causes of defects and errors in manufacturing and business processes.[1] It uses a set of quality management methods, including statistical methods, and creates a special infrastructure of people within the organization ("Black Belts" etc.) who are experts in these methods.[1] Each Six Sigma project carried out within an organization follows a defined sequence of steps and has quantified financial targets (cost reduction or profit increase).[1]
Contents[hide]
1 Historical overview
1.1 Origin and meaning of the term "six sigma process"
1.1.1 The role of the 1.5 sigma shift
1.1.2 Sigma levels
2 Methodology
2.1 DMAIC
2.2 DMADV
3 Implementation roles
4 Quality management tools and methodologies used in Six Sigma
5 Software used for Six Sigma
6 List of Six Sigma companies
7 Reception
7.1 Lack of originality
7.2 Role of consultants
7.3 Studies that indicate negative effects caused by Six Sigma
7.4 Based on arbitrary standards
7.5 Criticism of the 1.5 sigma shift
8 Notes
9 Literature
10 See also
11 External links
//

[edit] Historical overview
Six Sigma was originally developed as a set of practices designed to improve manufacturing processes and eliminate defects, but its application was subsequently extended to other types of business processes as well.[2] In Six Sigma, a defect is defined as anything that could lead to customer dissatisfaction.[1]
The particulars of the methodology were first formulated by Bill Smith at Motorola in 1986.[3] Six Sigma was heavily inspired by six preceding decades of quality improvement methodologies such as quality control, TQM, and Zero Defects, based on the work of pioneers such as Shewhart, Deming, Juran, Ishikawa, Taguchi and others.
Like its predecessors, Six Sigma asserts that –
Continuous efforts to achieve stable and predictable process results (i.e. reduce process variation) are of vital importance to business success.
Manufacturing and business processes have characteristics that can be measured, analyzed, improved and controlled.
Achieving sustained quality improvement requires commitment from the entire organization, particularly from top-level management.
Features that set Six Sigma apart from previous quality improvement initiatives include –
A clear focus on achieving measurable and quantifiable financial returns from any Six Sigma project.[1]
An increased emphasis on strong and passionate management leadership and support.[1]
A special infrastructure of "Champions," "Master Black Belts," "Black Belts," etc. to lead and implement the Six Sigma approach.[1]
A clear commitment to making decisions on the basis of verifiable data, rather than assumptions and guesswork.[1]
The term "Six Sigma" is derived from a field of statistics known as process capability studies. Originally, it referred to the ability of manufacturing processes to produce a very high proportion of output within specification. Processes that operate with "six sigma quality" over the short term are assumed to produce long-term defect levels below 3.4 defects per million opportunities (DPMO).[4][5] Six Sigma's implicit goal is to improve all processes to that level of quality or better.
Six Sigma is a registered service mark and trademark of Motorola, Inc.[6] Motorola has reported over US$17 billion in savings[7] from Six Sigma as of 2006.
Other early adopters of Six Sigma who achieved well-publicized success include Honeywell International (previously known as Allied Signal) and General Electric, where the method was introduced by Jack Welch.[8] By the late 1990s, about two-thirds of the Fortune 500 organizations had begun Six Sigma initiatives with the aim of reducing costs and improving quality.[9]
In recent years, Six Sigma has sometimes been combined with lean manufacturing to yield a methodology named Lean Six Sigma.

Graph of the normal distribution, which underlies the statistical assumptions of the Six Sigma model. The Greek letter σ marks the distance on the horizontal axis between the mean, µ, and the curve's point of inflection. The greater this distance is, the greater is the spread of values encountered. For the curve shown in red above, µ = 0 and σ = 1. The other curves illustrate different values of µ and σ.

[edit] Origin and meaning of the term "six sigma process"
The following outlines the statistical background of the term Six Sigma.
Sigma (the lower-case Greek letter σ) is used to represent the standard deviation (a measure of variation) of a statistical population. The term "six sigma process" comes from the notion that if one has six standard deviations between the mean of a process and the nearest specification limit, there will be practically no items that fail to meet the specifications.[5] This is based on the calculation method employed in a process capability study.
In a capability study, the number of standard deviations between the process mean and the nearest specification limit is given in sigma units. As process standard deviation goes up, or the mean of the process moves away from the center of the tolerance, fewer standard deviations will fit between the mean and the nearest specification limit, decreasing the sigma number.[5]

[edit] The role of the 1.5 sigma shift
Experience has shown that in the long term, processes usually do not perform as well as they do in the short.[5] As a result, the number of sigmas that will fit between the process mean and the nearest specification limit is likely to drop over time, compared to an initial short-term study.[5] To account for this real-life increase in process variation over time, an empirically-based 1.5 sigma shift is introduced into the calculation.[10][5] According to this idea, a process that fits six sigmas between the process mean and the nearest specification limit in a short-term study will in the long term only fit 4.5 sigmas – either because the process mean will move over time, or because the long-term standard deviation of the process will be greater than that observed in the short term, or both.[5]
Hence the widely accepted definition of a six sigma process is one that produces 3.4 defective parts per million opportunities (DPMO).[11] This is based on the fact that a process that is normally distributed will have 3.4 parts per million beyond a point that is 4.5 standard deviations above or below the mean (one-sided capability study).[5] So the 3.4 DPMO of a "Six Sigma" process in fact corresponds to 4.5 sigmas, namely 6 sigmas minus the 1.5 sigma shift introduced to account for long-term variation.[5] This is designed to prevent underestimation of the defect levels likely to be encountered in real-life operation.[5]

[edit] Sigma levels
Taking the 1.5 sigma shift into account, short-term sigma levels correspond to the following long-term DPMO values (one-sided):
One Sigma = 690,000 DPMO = 31% efficiency
Two Sigma = 308,000 DPMO = 69.2% efficiency
Three Sigma = 66,800 DPMO = 93.32% efficiency
Four Sigma = 6,210 DPMO = 99.379% efficiency
Five Sigma = 230 DPMO = 99.977% efficiency
Six Sigma = 3.4 DPMO = 99.9997% efficiency

[edit] Methodology
Six Sigma has two key methodologies: [9] DMAIC and DMADV, both inspired by Deming's Plan-Do-Check-Act Cycle. DMAIC is used to improve an existing business process; DMADV is used to create new product or process designs.[9]

[edit] DMAIC
The basic methodology consists of the following five steps:
Define process improvement goals that are consistent with customer demands and the enterprise strategy.
Measure key aspects of the current process and collect relevant data.
Analyze the data to verify cause-and-effect relationships. Determine what the relationships are, and attempt to ensure that all factors have been considered.
Improve or optimize the process based upon data analysis using techniques like Design of Experiments.
Control to ensure that any deviations from target are corrected before they result in defects. Set up pilot runs to establish process capability, move on to production, set up control mechanisms and continuously monitor the process.

[edit] DMADV
The basic methodology consists of the following five steps:
Define design goals that are consistent with customer demands and the enterprise strategy.
Measure and identify CTQs (characteristics that are Critical To Quality), product capabilities, production process capability, and risks.
Analyze to develop and design alternatives, create a high-level design and evaluate design capability to select the best design.
Design details, optimize the design, and plan for design verification. This phase may require simulations.
Verify the design, set up pilot runs, implement the production process and hand it over to the process owners.
DMADV is also known as DFSS, an abbreviation of "Design For Six Sigma".[9]

[edit] Implementation roles
One of the key innovations of Six Sigma is the professionalizing of quality management functions. Prior to Six Sigma, quality management in practice was largely relegated to the production floor and to statisticians in a separate quality department. Six Sigma borrows martial arts ranking terminology to define a hierarchy (and career path) that cuts across all business functions and a promotion path straight into the executive suite.
Six Sigma identifies several key roles for its successful implementation.[12]
Executive Leadership includes the CEO and other members of top management. They are responsible for setting up a vision for Six Sigma implementation. They also empower the other role holders with the freedom and resources to explore new ideas for breakthrough improvements.
Champions are responsible for Six Sigma implementation across the organization in an integrated manner. The Executive Leadership draws them from upper management. Champions also act as mentors to Black Belts.
Master Black Belts, identified by champions, act as in-house coaches on Six Sigma. They devote 100% of their time to Six Sigma. They assist champions and guide Black Belts and Green Belts. Apart from statistical tasks, their time is spent on ensuring consistent application of Six Sigma across various functions and departments.
Black Belts operate under Master Black Belts to apply Six Sigma methodology to specific projects. They devote 100% of their time to Six Sigma. They primarily focus on Six Sigma project execution, whereas Champions and Master Black Belts focus on identifying projects/functions for Six Sigma.
Green Belts are the employees who take up Six Sigma implementation along with their other job responsibilities. They operate under the guidance of Black Belts.

[edit] Quality management tools and methodologies used in Six Sigma
Six Sigma makes use of a great number of established quality management methods that are also used outside of Six Sigma. The following table shows an overview of the main methods used.
5 Whys
Analysis of variance
ANOVA Gage R&R
Axiomatic design
Business process mapping
Catapult exercise on variability
Cause & effects diagram (also known as fishbone or Ishikawa diagram)
Chi-square test of independence and fits
Control chart
Correlation
Cost-benefit analysis
CTQ tree
Customer survey through use of Enterprise Feedback Management (EFM) systems
Design of experiments
Failure mode and effects analysis
General linear model
Histograms
Homogeneity of variance
Pareto chart
Pick chart
Process capability
Regression analysis
Root cause analysis
Run charts
SIPOC analysis (Suppliers, Inputs, Process, Outputs, Customers)
Stratification
Taguchi methods
Thought process map
TRIZ

[edit] Software used for Six Sigma
Main article: List of Six Sigma software packages

[edit] List of Six Sigma companies
Main article: List of Six Sigma companies

[edit] Reception
Six Sigma has made a huge impact on industry and is widely employed as a business strategy for achieving and sustaining operational and service excellence.[1] However, there have also been various criticisms of Six Sigma.

[edit] Lack of originality
Noted quality expert Joseph Juran has described Six Sigma as "a basic version of quality improvement," stating that "[t]here is nothing new there. It includes what we used to call facilitators. They've adopted more flamboyant terms, like belts with different colors. I think that concept has merit to set apart, to create specialists who can be very helpful. Again, that's not a new idea. The American Society for Quality long ago established certificates, such as for reliability engineers."[13]

[edit] Role of consultants
The use of "Black Belts" as itinerant change agents is controversial as it has created a cottage industry of training and certification. Six Sigma is often oversold by consulting firms that claim expertise in Six Sigma when they in fact only have a rudimentary understanding of the tools and techniques and the Six Sigma approach.[1]
The expansion of the various "Belts" to include "Green Belts," "Master Black Belts" and "Gold Belts" is commonly seen as a parallel to the various "belt factories" that exist in martial arts.[citation needed]

[edit] Studies that indicate negative effects caused by Six Sigma
A Fortune article stated that "of 58 large companies that have announced Six Sigma programs, 91 percent have trailed the S&P 500 since." The statement is attributed to "an analysis by Charles Holland of consulting firm Qualpro (which espouses a competing quality-improvement process)."[14] The gist of the article is that Six Sigma is effective at what it is intended to do, but that it is "narrowly designed to fix an existing process" and does not help in "coming up with new products or disruptive technologies." Many of these claims have been argued as being in error or ill-informed.[15][16]
A Business Week article says that James McNerney's introduction of Six Sigma at 3M may have had the effect of stifling creativity. It cites two Wharton School professors who say that Six Sigma leads to incremental innovation at the expense of blue-sky work.[17]

[edit] Based on arbitrary standards
While 3.4 defects per million opportunities might work well for certain products/processes, it might not be ideal or cost-effective for others. A pacemaker might need higher standards, for example, whereas a direct mail advertising campaign might need lower ones. The basis and justification for choosing 6 as the number of standard deviations is not clearly explained.[18] In addition, the Six Sigma model assumes that the process data always conform to the normal distribution. The calculation of defect rates for situations where the normal distribution model does not apply is not properly addressed in the current Six Sigma literature.[1]

[edit] Criticism of the 1.5 sigma shift
Because of its arbitrary nature, the 1.5 sigma shift has been dismissed as "goofy" by the statistician Donald J. Wheeler.[19] Its universal applicability is seen as doubtful.[1]
The 1.5 sigma shift has also been contentious because it results in stated "sigma levels" that reflect short-term rather than long-term performance: a process that has long-term defect levels corresponding to 4.5 sigma performance is, by Six Sigma convention, described as a "6 sigma process."[5][20] The accepted Six Sigma scoring system thus cannot be equated to actual normal distribution probabilities for the stated number of standard deviations, and this has been a key bone of contention about how Six Sigma measures are defined.[20] The fact that it is rarely explained that a "6 sigma" process will have long-term defect rates corresponding to 4.5 sigma performance rather than actual 6 sigma performance has led several commentators to express the opinion that Six Sigma is a confidence trick.[5]

What should I say about this?

At first I would like to recollect, its ma first Ganesh festival celebration after 4 years. The reason is since I was not present in Maharashtra due to completion of ma Grads in Karnataka State, This is ma first time enjoying the festive along then. Ahoy! It feels so living to see those ganesh mandals, those electrifying “Kaaryakartas”, hair raiser decorations and above all tones n really tones of seeing girls who came along to visit various ganesh mandals! There is nothing like it. Absolutely Beautiful environment at this specific time of year.This year ma colony residents decided to reside Ganesh Idol on the main crossroad. Looking back I still remember ma colony residents have been always come first to celebrate this kinda festive through out the year like ganesh festive, Navratri, Gokulastami, etc. But since last three four years due to some residents death n all other mishaps our Mandal couldn’t place any event of any sort. So those were really soggy years I still feel. But this year it feels so awakening, cozza arrangement of placing ganesh idol again on ma favorite crossroad of ma town. This year we have placed an idol of seven n half feet tall and its so cute n adorable. How can anyone feel better than this afta such a long time! I just luv it man.
So, now comes the real story. One of ma closest friend “bhatya” came to ma place n argued for a visit to all town mandals decoration. As usual I denied at first. But later I found it quite irritating to misconduct him. Then I got stride on his super kool “M80” sorta scooter sorta moped sorta bike. Later I found it nothing but a yawning ride. Then we came to a Mandal called as “Bhagwa chowk mirtra Mandal”. This year what I explored is all mandals were in competition to organize a well settled live performance by Mandal Kaaryakartas. Pin pointing at this Mandal, they were performing a “NAATAK” named ‘ganesh raaya bharat varsha vachavaya’. At first it seemed nothing but a simple orthodox play. But when I saw the ‘sutradhaar’ I mean it’s the anchor of the play. It was a gurl. She’s fairer than average, cat eyes, actually Hazel eyes! She may be just half a feet shorter than me. I guess her shorter than half a feet to me. Then, sorta little bit light brown streax in middle brown hair. Hair till lower neck. Free ear lobes. Gorgeous nose up point. So authentically carved Hips! Stunning feet. Much more than complex expressions while playing a defined role. Full throttled energy while dancing, extremely cute movements while leaving the stage. Extremely cute nah actually I feel I have really never seen a gurl widh such cute movements in this life. She was in pure Marathi ethnic dress up. She had worn a naavvari sari! I remember it was maroon colored. And a lovely ornament called “NATH” on the nose. It’s like a nose ring. Basically a longed version of it. It’s made up of pearls n gold widh a shinning star on top of it! She looked sooooooooooooo beautiful. I really couldn’t believe I could ever notice a gurl as perfect as HER. She seemed nothing but a perfect bride to me. But now comes the fuckin best part of this lovely stance share between her n me. I was completely drowned in just staring at her. Bhoy she caught me while doing so. She took me noticing, though I was covered in a whole herd of other animals called people. Ma heart beat skipped forty fifty beats! Really. Then she kept noticing me in between the play again n again. I did the same. I felt sumthing weird here. I was luvin it though!Now I wanted to check if she was really checkin me out. Today is the second day I went to same Mandal n stared here like a wild stag again. At beginning I was at ma usual place. She saw me! Quickly her expressions were deeper. Much more living. She was I can say ACTIVE. The thing came to ma mind was, I felt she was just waiting for ma arrival. Seeing me she looked so enthralled. I want to make a mark here. I REALLY LUVED HER WAY OF ANTICIPATIN ME. I just felt there was none but just me n her on the stage. Same freaking exactly like bollywood. I kept lookin at her widh out missing a blink of an eye. She did the same whenever she got chance. I loved those moments from the bottom of ma heart! I don’t even remember how the first time of the play ended. I kept lookin at her n that’s it. Today I was widh ma best mate “Sumba”. I had told him bout the nicehap, a day before. So he had accompanied me to analyze it. He made it affirmative to go for a true relationship till the end of time seeing both of us involved from a distance yet so churned twists in it. I luv her in all way. But here I want to say I dunno know if I m in true luv o wadeva called as luv at first sight. Notice to ma GFs! Gurls play safe. Don’t take it personally. I still feel it confusing if its luv, I mean true luv to her. So stay in peace. M still yours till now. I mean till this moment. Whatever! But can’t say hence forth. Ha ha ha ha! I know m dickhead! Afta the first time of the play I was eager to see HER back. Alas ! she came back on stage. I was relieved! I wanted her badly. I like her so much! It feels she had the same feeling too. Just cozza lookin her smile at me. I admired her open heartedly! But this time she hadn’t have her “NATH” tucked to her nose. Still she appeared so freaking gorgeous. Really very pure, innocent, complete! I was feeling uncomfortable to make any kinda signal to her. But I dared anyhow. I signaled her while she stared at me as if where was her nose ring I mean her ‘nath’ with the help of ma hands n fingers. Man she absorbed it so smoothly. As soon as the second turn of the play ended, I was again waiting for her to come on stage. Those five to seven minutes were really killers. As soon as I herd the announcement of the start of the play I jumped to ma usual place of standing n lookin for her. I wanted to check if she really was noticing me or just playing widh the eyesight of hers. I was nervous to know if she had worn the ‘nath’ this time o not. It was going to define whole lot complexions between us. It was going to prove if we really shared a world of our own in those two days o not. It meant a lot to me though. But when I saw, she was back on stage, I was welcomed widh a deep flourishing smile from her accompanied widh the beautiful ‘nath’ placed on the left side of her nose. It felt so sweet. Really so pacifying at heart. I think I can guess if I m in love this time. I want it to be TRUE LUV THIS TIME! Lord Ganesh please listen to me this time. I felt to go n kiss her gently for being ma silence lover for the two days, n I promise I wont forget her till the end of ma life. I still have goose worms remembering her. She looked so many times at me. N so I did. I wish never comes an end between her n me. I sorta luv that gurl. M proved she loves me too. This aint one sided traffic. I want to talk to her. I want to caress her. I want to make her mine. FOREVER !

whorl whorl whorl !

"ha ha ha ha ha ha i dunno !"thats ma favourite words bout everything.......bout life... bout gurls.... bout money....bout troubles...bout....ummmm i dunno ! ha ha ha ha nways today i got a call from an unkown no. as usual... guess... yeah it was a gurl asusual again ! ha ha ha her name's Dishadisha kulkarni. nice sweet voice.. bit of encrypeted words. i had yelled at her for givin miss calls without knowin whose no. it is. she wasbit of shattered hearin ma cranking tone. later she accepted her mistake n asked if i cud be her frnd. i was quite amazzed how gurls change topicso there after. GURLS are WEIRD. i was affirmative to her open frndship as usual of any gurls open relation. Later talkin to her felt she's too ritualistic.i think too much of it. har ek baat main BHAGWAN. at the end she sounds sumthin different. nice way of goin into frndship. he he he ! saala bhukha darinda ! hey ram..... sare ladkiyon ke wrong no.s mere hi no pe aane hain kya .... puk gaya hoon ... still it feels better.... who doesnt want to talk to gurl.. ! though gurls r brainless.... i mean most of them. ok ok about disha, she is sumthin weird i mean specifically she is ummm well... she sounds pandora's box. quite an appealin SEXY voice! fuck m again on ma track..... BHAGWAN main kab sudhrunga ??nways, i rest in PEACE again ! thnx almighty LORD !

I may never see tomorrow, there's no written guaranteeand things that happened yesterday belong to history.I cannot predict the future, I cant change the past.I have just the present moment, I must treat it as my last.I must use the moment wisely, For it soon will pass awayAnd be lost to me forever, As a part of yesterday.I must exercise compasion, Help the fallen to their feet.Be a friend to the friendless, Make an empty life complete.I may not have another chance, On bended knee to pray,And thankgod with humble heart for giving me the day.