MODULE 7Quality Control Tools
The seven QC tools are the most popular tools, which are being used by quality conscious companies throughout the world for improvement of quality of products and processes. A brief description of these tools is presented here:Cause-and-Effect DiagramsFlowchartsChecklistsControl ChartsScatter DiagramsPareto AnalysisHistograms
7 Quality Control tools
Cause-and-Effect DiagramsCalled Fishbone Diagram or Ishikawa diagramFocused on solving identified quality problem
FlowchartsUsed to document the detailed steps in a processOften the first step in Process Re-Engineering
ChecklistSimple data check-off sheet designed to identify type of quality problems at each work station; per shift, per machine, per operator
Control ChartsImportant tool used in Statistical Process ControlThe UCL and LCL are calculated limits used to show when process is in or out of control
Scatter DiagramsA graph that shows how two variables are related to one anotherData can be used in a regression analysis to establish equation for the relationship
Pareto AnalysisTechnique that displays the degree of importance for each elementNamed after the 19th century Italian economistOften called the 80-20 RulePrinciple is that quality problems are the result of only a few problems e.g. 80% of the problems caused by 20% of causes
HistogramsA chart that shows the frequency distribution of observed values of a variable like service time at a bank drive-up windowDisplays whether the distribution is symmetrical (normal) or skewed
Six Sigma (6)Six Sigma is a business management strategy originally developed by Motorola. As of 2009, it enjoys widespread application in many sectorsSix Sigma is a fact-based data driven structured methodology that is used to create breakthrough improvements in business processes with a strong focus on customer needs. It is used to solve tough business problems when the root cause of the problem or the solution is not known.
Six Sigma (6)A performance goal, representing 3.4 defects for every million opportunities to make one.A series of tools and methods used to improve or design products, processes, and/or services.A statistical measure indicating the number of standard deviations within customer expectations.A disciplined, fact-based approach to managing a business and its processes.A means to promote greater awareness of customer needs, performance measurement, and business improvement.
Examples of the Sigma ScaleIn a world at 3 sigma. . .
There are 964 U.S. flight cancellations per day.
The police make 7 false arrests every 4 minutes.
In Massachusetts, 5,390 newborns are dropped each year.In one hour, 47,283 international long distance calls are accidentally disconnected.In a world at 6 sigma. . .
1 U.S. flight is cancelled every 3 weeks.
There are fewer than 4 false arrests per month.
1 newborn is dropped every 4 years in Massachusetts.
It would take more than 2 years to see the same number of dropped international calls.
D M A I CDefineMeasureAnalyzeImproveControlImprovement methodology
Six Sigma DMAICDMAIC Define the project goals and customer (internal and external) deliverables Measure the process to determine current performance Analyze and determine the root cause(s) of the defects Improve the process by eliminating defects Control future process performanceWhen To Use DMAICThe DMAIC methodology, instead of the DMADV methodology, should be used when a product or process is in existence at your company but is not meeting customer specification or is not performing adequately.
Six Sigma DMADVDMADV Define the project goals and customer (internal and external) deliverables Measure and determine customer needs and specifications Analyze the process options to meet the customer needs Design (detailed) the process to meet the customer needs Verify the design performance and ability to meet customer needs When To Use DMADVA product or process is not in existence at your company and one needs to be developed The existing product or process exists and has been optimized (using either DMAIC or not) and still doesn't meet the level of customer specification or six sigma level
DMAIC Versus DMADVThe Similarities of DMAIC and DMADVSix Sigma methodologies used to drive defects to less than 3.4 per million opportunities. Data intensive solution approaches. Intuition has no place in Six Sigma -- only cold, hard facts. Implemented by Green Belts, Black Belts and Master Black Belts. Ways to help meet the business/financial bottom-line numbers. Implemented with the support of a champion and process owner
A quality circle is a volunteer group composed of workers who meet together to discuss workplace improvement, and make presentations to management with their ideas. Typical topics are improving safety, improving product design, and improvement in manufacturing.Quality Circles
Quality CirclesGroup of employees who meet regularly to solve problemsQuality Circles are small groups of people who do similar or related work and meet regularly to identify, analyse,and solve product-quality and production problems and to improve general operations.Trained in planning, problem solving, and statistical methodsOften led by a facilitatorVery effective when done properly
VolunteersSet Rules and PrioritiesDecisions made by ConsensusUse of organized approaches to Problem-SolvingAll members of a Circle need to receive trainingMembers need to be empoweredMembers need to have the support of Senior Management
Organization and PlanningBenefits of Quality CirclesImproved communicationGreater job satisfactionImproved moraleImproved qualityCost savings
Organization and Planning
The Quality Circle Process
An analysis tool that provides a systematic way of looking at effects and their respective causesDeveloped by Dr. Kaoru Ishikawa of Japan in 1943 and is sometimes referred to as an Ishikawa Diagram or a Fishbone Diagram because of its shape
Cause and effect diagram
Basic Use of the CE DiagramThe CE Diagram is basically used to investigate a problem, exploring, identifying, and displaying the possible causes.
Purpose of the CE DiagramTo identify the relationship between the effects in a given situation and all of the possible causes
To find problem sources/solutions
*Key point :-
6 sigma 5 step improvement methodology*