What is Six Sigma ? The term " Sigma " is used to designate the distribution or spread about the mean (average) of any process or procedure. For a business or manufacturing process, the sigma value is a metric that indicates how well that process is performing. The higher the sigma value, the better. Sigma measures the capability of the process to perform defect-free-work. A defect is anything that results in customer dissatisfaction.
With Sig Sigma, the common measurement index is "defects-per-unit," where a unit can be virtually anything--- a component, piece of material, line of code, administrative form, time frame, distance, etc. The Sigma value indicates how often defects are likely to occur. The higher the sigma value, the less likely a process will produce defects. As sigma increases, costs go down, cycle time goes down, and customer satisfaction goes up. What is Six Sigma … ?
THE SIX SIGMA EVOLUTIONARY TIMELINE 1736 : French mathematician Abraham de Moivre publishes an article introducing the normal curve. 1896 : Italian sociologist Vilfredo Alfredo Pareto introduces the 80/20 rule and the Pareto distribution in Cours d’Economie Politique . 1924 : Walter A. Shewhart introduces the control chart and the distinction of special vs. common cause variation as contributors to process problems. 1941 : Alex Osborn, head of BBDO Advertising, fathers a widely-adopted set of rules for “brainstorming”. 1949 : U. S. DOD issues Military Procedure MIL-P-1629, Procedures for Performing a Failure Mode Effects and Criticality Analysis . 1960 : Kaoru Ishikawa introduces his now famous cause-and-effect diagram. 1818 : Gauss uses the normal curve to explore the mathematics of error analysis for measurement, probability analysis, and hypothesis testing. 1970s : Dr. Noriaki Kano introduces his two-dimensional quality model and the three types of quality. 1986 : Bill Smith, a senior engineer and scientist introduces the concept of Six Sigma at Motorola 1994 : Larry Bossidy launches Six Sigma at Allied Signal. 1995 : Jack Welch launches Six Sigma at GE.
DMAIC – THE IMPROVEMENT METHODOLOGY D efine M easure A nalyze I mprove C ontrol Objective : DEFINE the opportunity Objective : MEASURE current performance Objective : ANALYZE the root causes of problems Objective : IMPROVE the process to eliminate root causes Objective : CONTROL the process to sustain the gains.
What is the problem? The “problem” is the Output (a “Y” in a math equation Y=f(x1,x2,x3) etc).
What is the cost of this problem
Who are the stake holders / decision makers
Align resources and expectations
Project Charter Voice of the Stakeholder Six Sigma $ Cost of Poor Quality
DEFINE – CUSTOMER REQUIREMENTS WHAT ARE THE CTQS? WHAT MOTIVATES THE CUSTOMER? Voice of the Customer Key Customer Issue Critical to Quality SECONDARY RESEARCH PRIMARY RESEARCH Surveys OTM Industry Intel Listening Posts Market Data Industry Benchmarking Focus Groups Customer Service Customer Correspondence Obser-vations
MEASURE – BASELINES AND CAPABILITY WHAT IS OUR CURRENT LEVEL OF PERFORMANCE?
Sample some data / not all data
Current Process actuals measured against the Customer expectation
What is the chance that we will succeed at this level every time?
ANALYZE – POTENTIAL ROOT CAUSES WHAT AFFECTS OUR PROCESS? y = f (x 1 , x 2 , x 3 . . . x n ) Ishikawa Diagram (Fishbone) Six Sigma
ANALYZE – VALIDATED ROOT CAUSES WHAT ARE THE KEY ROOT CAUSES? y = f (x 1 , x 2 , x 3 . . . x n ) Critical Xs Process Simulation Data Stratification Regression Analysis Six Sigma
IMPROVE – POTENTIAL SOLUTIONS HOW CAN WE ADDRESS THE ROOT CAUSES WE IDENTIFIED?
Address the causes, not the symptoms.
Decision y = f (x 1 , x 2 , x 3 . . . x n ) Critical Xs Evaluate Clarify Generate Divergent | Convergent
IMPROVE – SOLUTION SELECTION HOW DO WE CHOOSE THE BEST SOLUTION? Solution Implementation Plan Solution Selection Matrix Solution Sigma Time CBA Other Score Time Quality Cost Six Sigma ☺ Nice Try Nice Idea X Solution Right Wrong Implementation Bad Good
CONTROL – SUSTAINABLE BENEFITS HOW DO WE ”HOLD THE GAINS” OF OUR NEW PROCESS?
Some variation is normal and OK
How High and Low can an “X” go yet not materially impact the “Y”
Pre-plan approach for control exceptions
DFSS – THE DESIGN METHODOLOGY D ESIGN F OR S IX S IGMA
Design new processes, products, and/or services from scratch
Replace old processes where improvement will not suffice
Differences between DFSS and DMAIC
Projects typically longer than 4-6 months
Extensive definition of Customer Requirements (CTQs)
Heavy emphasis on benchmarking and simulation; less emphasis on base lining