Six Sigma: Ankit Vijayvargiya

Six Sigma

SIX SIGMA ANKIT VIJAYVARGIYA

Six Sigma

What is Six Sigma? Six Sigma is a highly disciplined process that helps us focus on developing and delivering nearperfect products and services. Why ”Sigma“? The word is a statistical term that measures how far a given process deviates from perfection. The central idea behind Six Sigma is that if you can measure how many “defects” you have in a process, you can systematically figure out how to eliminate them and get as close to “zero defects” as possible. 2

Six Sigma

Sigma (σ) A term used in statistics to represent standard deviation, an indicator of the degree of variation in a set of measurements or a process. A one-sigma process produces 691462.5 defects per million opportunities—a percentage of satisfactory outputs of only 30.854%.

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Six Sigma

Standard deviation A measure of the spread of data points in relation to the mean. It’s the most common measure of variation in a set of data

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Six Sigma

Six Sigma A philosophy of managing that focuses on eliminating defects through practices that emphasize understanding, measuring, and improving processes. It’s based on the statistical concept of six sigma, measuring a process at only 3.4 defects per million opportunities (DPMO).

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Six Sigma

DPMO at sigma levels

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Six Sigma

HISTORICAL PERSPECTIVE ON SIX SIGMA In the mid-1980s, Motorola, under the leadership of Robert W. Galvin, was the initial developer of Six Sigma. Most credit the late Bill Smith for inventing Six Sigma; Smith, a senior engineer and scientist with n Motorola’s Communications Division, had noted that its final product tests had not predicted the high level of system failure rates Motorola was experiencing. He suggested that the increasing level of complexity of the system and the resulting high number of opportunities for failure could be possible causes for this. He came to the conclusion that Motorola needed to require a higher level of internal quality, and he brought this idea to then-CEO Bob Galvin’s attention, persuading him that Six Sigma should be set as a quality goal. 7

Six Sigma

Six Sigma: DMAIC Methodology • Define • Measure • Analyze • Improve • Control

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Six Sigma

Define Key Items • • • • •

Customers, Value, Problem Statement Scope, Timeline, Team Primary/Secondary & OpEx Metrics Current Value Stream Map Voice Of Customer (QFD) (Quality Function Deployment)

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Measure

Six Sigma

• Establish measurement capability • Validate the database (transactional) • Gage R&R (Repeatability & Reproducibility) • Calibration is not enough • Many (or most) measurement systems are not capable • How good is the data you are using to make decisions?

• Fix the measurement system • Enables calculation of process capability • Enables calculation of alpha & beta risks • This step is often skipped 10

Analyze (and fix the obvious)

Six Sigma

• Find all KPOVs & KPIVs (Key Process Output Variables; Key Process Input Variables)

• FMEA, DOE, critical Xs, VA/NVA (Failure Modes Effects Analysis; Design Of Experiment)

• Graphical Analysis, ANOVA (Analysis Of Variance)

• Future Value Stream Map 11

Improve

Six Sigma

• Optimize KPOVs & test the KPIVs (Key Process Output Variables; Key Process Input Variables)

• Redesign process, set pacemaker • 5S, Cell design, MRS (Material Replenishment System)

• Visual controls • Value Stream Plan 12

Control

Six Sigma

• Management of Change • Owned by project champion and value stream manager • Critical to long term success of project • Physical and cultural changes

• Measurement controls • On-going metrics

• Visual Controls • Enable workers to self-manage the process

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Define Customers, Value, Problem Statement Scope, Timeline, Team Primary/Secondary & OpEx Metrics

Next Project

Current Value Stream Map

Validate Project $

Six Sigma

Voice Of Customer (QFD)

Celebrate Project $

Measure

Control

Assess specification / Demand

Document process (WIs, Std Work)

Measurement Capability (Gage R&R)

Mistake proof, TT sheet, CI List

Correct the measurement system

Analyze change in metrics

Process map, Spaghetti, Time obs.

Value Stream Review

Measure OVs & IVs / Queues

Prepare final report

Validate Project $ Validate Project $

Improve

Analyze (and fix the obvious)

Optimize KPOVs & test the KPIVs Redesign process, set pacemaker 5S, Cell design, MRS Visual controls Value Stream Plan

Root Cause (Pareto, C&E, brainstorm)

Validate Project $

Find all KPOVs & KPIVs FMEA, DOE, critical Xs, VA/NVA Graphical Analysis, ANOVA Future Value Stream Map

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Plan

Execute • • • • • •

Six Sigma

Identify Problem

Strategic Link to Business Plan defined in Project Selection Process Defined Business Impact with Op Ex Champion support Structured Brainstorming at all organizational levels Cause and Effect Diagrams identifying critical factors Primary and Secondary Metrics defined and charted Multi-Level Pareto Charts to confirm project focus

Practical Problem

• • • • • •

Problem Definition

• Characterize the response, look at the raw data • Abnormal? Other Clues? Mean or Variance problem? • Time Observation • Spaghetti Diagram • Takt Time • Future State Maps • Percent Loading • Standard Work Combination • Use Graphical Analysis, Multi-Vari, ANOVA and basic statistical tools to identify the likely families of variability

Problem Solution

• • • • • • •

Problem Control Execute

Plan

Develop a focused Problem Statement and Objective Develop a Process Map and/or FMEA Develop a Current State Map Identify the response variable(s) and how to measure them Analyze measurement system capability Assess the specification (Is one in place? Is it the right one?)

Identify the likely X’s 5S • Set Up Time Reduction (SMED) Material Replenishment Systems Level Loading / Line Leveling Cell Design • Visual Controls Use Design of Experiments to find the critical few X’s Move the distribution; Shrink the spread; Confirm the results

• Mistake Proof the process (PokaYoke) • Tolerance the process • Measure the final capability • Place appropriate process controls on the critical X’s • Document the effort and results

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Breakthrough performance gains

Six Sigma

(Distribution Shifted ± 1.5σ )

σσ

2 2 3 3 4 4 5 5 6 6 Process Process Capability Capability

PPM PPM

3 30 08 8,5 ,53 37 7 6 66 6,8 ,80 07 7 6 6,2 ,21 10 0 2 23 33 3 3 3.4 .4 Defects Defectsper perMillion Million Opportunities Opportunities 16

Basic Implementation Roadmap

Six Sigma

Identify Customer Requirements

Understand and Define Entire Value Streams Vision (Strategic Business Plan)

Deploy Key Business Objectives - Measure and target (metrics)

- Align and involve all employees - Develop and motivate Continuous Improvement (DMAIC)

Define, Measure, Analyze, Improve Identify root causes, prioritize, eliminate waste, make things flow and pulled by customers

Control -Sustain Improvement -Drive Towards Perfection 17

Six Sigma

The Normal Curve and Capability Excellent Process Capability

Poor Process Capability Very High Probability of Defects

Very High Probability of Defects

LSL

USL

Low LowSigma Sigma

Very Low Probability of Defects

Very Low Probability of Defects

LSL

USL

High HighSigma Sigma

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What about Lean, TOC, TQM

Six Sigma

• Six Sigma • Remove defects, minimize variance

• Lean • Remove waste, shorten the flow

• TOC • Remove and manage constraints

• TQM • Continuous Improvement

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Does it work?.

In Billions $

1999 73 companies Ralston Purina Quaker Oats Hilton Hotels Coca-Cola Unilever etc.

Market Value Added

Six Sigma

The top companies in Customer Satisfaction grow MVA at nearly twice the rate of their poor-performing counterparts.

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$42

40 30

$23

20 10 0 Low

High

Customer Satisfaction Index Score Source: American Customer Satisfaction Index, U Michigan, HBR, 2001 20