Six sigma methodology for quality control

Six Sigma methodology was first introduce by Motorola in 1987 by an Engineer name Bill Smith and gets fully support by Bob Galvin of Motorola as the CEO at the time as a strategy to improve and enhance process and quality control (process Improvement and Quality Control) at his company.

Six Sigma to fame and became popular worldwide after Jack Welch to use it as a business strategy in General Electric (GE) in 1995. In General, Six Sigma is a methodology use to conduct the repair efforts and continuous process improvement or continuously (Continuous Improvement).

Overview

SIX SIGMA comes from the word which means "SIX six (6) and SIGMA is the Standard Deviation of the unit which is also denote by the symbol σ, Six Sigma is also often in the symbolize be 6 σ. The higher the Sigma, the better the pula quality.

In other words, the higher the Sigma-it’s getting lower also the level of disability or its failure. Like Sigma conversion Chart below. The strategy undertaken by the Six Sigma is:

• Focus on Customer Needs and Satisfaction (Customer Focus)


• Lower level of disability (Reduce Defects)


• Ranged around the Target Center (Center around the Target)


• Lower Variation (Reduce Variation)

Basic concepts of Six Sigma are actually derive from the combine concepts of TQM (Total Quality Management) and Statistical Process Control (SPC) where both the concept comes from the thoughts of experts. In the process, Six Sigma is a metric which was originally develop into a methodology and currently has become a management system.

In the implementation of Six Sigma, target top spot or process failure is control within the target of 3.4 DPMO (Defects per Million Opportunities or Failures per million opportunities) which means 1 million units of product produce there is only 3.4-unit handicap. Means the company producing the product with the level of customer satisfaction reaches 99.9997.

Level Positions for people in the Six Sigma Methodology is:

1. Champion/Sponsor (Top Management)


2. Master Black Belt


3. Black Belt


4. Green Belt


5. Team Members (Team Member)


6. Process Owner (owner or person working on the process)

Knowledge of the mandatory Statistical own for people using the Six Sigma Methodology is mainly on the position of the Green Belt, Black Belt and Master Black Belt.

To get the certification of Green Belt, Black Belt and Master Black Belt need special training and testing by the Agency's testers such as ASQ (United States) and SQI (Singapore).

There are 5 Stages to be used in Six Sigma problem solving known as DMAIC Method, namely:

DEFINE

That is the first stage in Six Sigma for defining and selecting all problems will be solve and their Costs, benefits and impact on Customers (customer). Tools (Tools) use in phases Define:

1. Function Deployment Process Folder


2. SIPOC Folder (Diagram Supplier, Input, process, Output and Customer)


3. Pareto Chart


4. FMEA (Failure Mode Effect Analysis)


5. Affinity Diagram


6. Relation Diagram


7. Cause and Effect Analysis (Fishbone Chart and Cause and Effect Matrix)


8. MEASURE

Measurement is the measurement of the Stage against a problem that has been define to be resolve. In this stage there is a data retrieval and then Measure their characteristics as well as the capability of the process at this point to determine what steps should be taken to make improvements and increase further.

Tools (Tools) that are use in the stage of Measurement are:

1. Cause and Effect Analysis (Fishbone Chart and Cause and Effect Matrix)


2. Probability Distributions (Distributions of Probability)


3. Basic Statistics such as the Mean, Median and Mode


4. Gage Repeatability and Reproducibility (GR & R)


5. Process Capability

ANALYSIS

The stage of the Analysis is the stage to find a solution to solve the problem base on Root Cause (root causes) that have identify. In this step, we must be able to analyze and validate against the root Problems (Root Causes) or solution via Hypothesis statements.

Tools (Tools) that are use in the stage of the Analysis is:

1. Hypothesis Testing


2. Regression


3. Correlation Analysis


4. ANOVA (Analysis of Variance)


5. Contingency Table

IMPROVE

After obtaining the root problems and solutions as well as download the validation, the next step is to conduct corrective actions against these problems by doing the testing and experimentation to be able to optimize the solution so that it really useful to solve the problems we are experiencing.

At the stage of Improvement, the tool use is the DOE or the Design of Experiment, consisting of:

1. Factorial Design


2. General Full Factorial Design


3. Fractional Factorial Design

CONTROL

The purpose of Control is to set the stage of Standardization as well as control and maintain the process that has been repair and improve in the long term and prevent potential problems that will occur at a later date or When there is a turnover process, labor as well as management turnover.

Tools (Tools) use in stages of Control are:

1. Poke Yoke (Mistake Proofing)


2. Process Control Plan


3. Process Control Chart