QUALITY TOOLS & TECHNIQUES

By: -Hakeem–Ur–Rehman

IQTM–PU 1

TQ TPROJECT CHARTER, CHECK SHEET, PARETO ANALYSIS, C & E DIAGRAM

& MATRIX

PROJECT CHARTER

Project Title Project Title

Business Case Why should you do this project? What are the benefits of doing this project?

Problem Statement What is the problem, issue and/or concern?

Goal What are your improvement objectives and targets?

Metrics (CTQ’s) PRIMARY Metric(s): Key measures to be used for the objectives SECONDARY Metric(s): Those measures which indicates impacts on

secondary concerns and which indicates that problem is not shifted to other key areas.

Project Scope What authority do you have? Which processes/products you are addressing? What is not within this project?

Project Team Who are the team leader, sponsor, and members? What are their roles and responsibilities in this project?

Project Plan How and when are you going to get this project done (DMAIC stages)

Communication Plan What are your interfaces with each other? What are your meeting & reporting times?

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TYPES OF DATAATTRIBUTE DATA give you counts representing the presence or absence of a characteristic or defect. These counts are based on the occurrence of discrete events, e.g.,

true/false statements Accepted or rejectedPassed or fail

An attribute is not numerically measured; it’s either there or it’s not.

VARIABLE DATA are based on numerical measurement of a key quality characteristic produced by the process, e.g.,

Diameter of a shaft Temperature of Oven Pressure of Steam, etc.

CHECK SHEET

A check sheet is a Form, in Diagram or Table format, prepared in advance for Recording/Collecting Data. You can thus gather necessary Data by just making a Check mark on the Sheet.

Main applications of a check sheet include registering how often different problems occur and registering the frequency of incidents that are believed to cause problems.

TYPES OF CHECK SHEET

There are five main types of check sheets used for data collection (custom check sheets can also be designed to fit specific needs):1. Defective item check sheet /

Attribute Check Sheet2. Variable Check Sheet 3. Defective Location Check Sheet 4. Defective Cause Check Sheet  5. Checkup Confirmation Check Sheet

TYPES OF CHECK SHEET DEFECTIVE ITEM (ATTRIBUTE) CHECK

SHEET: used to identify what types of problems or defects

are occurring in the process.  Usually these check sheets will have a list of the

defects or problems that may occur in the process.  When each sample is taken, a mark is placed in the

appropriate column whenever a defect or a problem has been identified. 

Countable data is used in the defective item check sheets.

TYPES OF CHECK SHEET VARIABLE CHECK SHEET:

Gathering data about a process also involves the collection of information about variables, such as size, length, weight, and diameter. These data are best represented by organizing the measurements into a frequency distribution on a variables check sheet. The following Figure is variables check sheet showing the frequency distribution of the length of logs in a sample of 95trees.

TYPES OF CHECK SHEET DEFECTIVE LOCATION CHECK SHEET:

Used to identify what types of problems or defects are occurring in the process.

Used to identify the location of the defect on the product.  Used; when the external appearance of the product is

important. Usually this type of check sheet consists of a picture of the

product. On this picture, marks can be made to indicate were defects are occurring on the surface of the product. 

TYPES OF CHECK SHEET DEFECTIVE CAUSE CHECK SHEET:

used to identify causes of a problem or a defect.  More than one variable or attribute is monitored

when collecting data for this type of check sheets.  For example, we could be collecting data about the

type of machine, operator, date, and time on the same check sheet. 

Operators Time Machine 1 Machine 2

Operator A Morning X X

Afternoon XX XXXXX

Operator B Morning X XX

Afternoon XX XXXXXXXXXX

As we can see most of the error is occurring at machine 2 and at the afternoon shift.  This could suggest that machine 2 has problems when it is run in the afternoon shift.

TYPES OF CHECK SHEET

CHECKUP CONFORMATION CHECK SHEET:Used to ensure that proper procedures are

being followed. These check sheets usually will have a list of

tasks that need to be accomplished before the action can be taken. 

Examples of checkup confirmation check sheets are final inspection, machine maintenance, operation checks, and service performance check sheets.  

PARETO ANALYSIS A bar graph used to arrange information in such a way that

priorities for process improvement can be established.

Count

Perc

ent

Fault Desc.

Count 43 107Percent 31.9 30.4 9.3 7.4 4.4 4.3 3.5

7072.0 1.9 4.8

Cum % 31.9 62.3 71.6 79.0 83.3 87.7

674

91.2 93.2 95.2 100.0

205 164 97 96 78 45

Other

Misc

. Defec

ts

Trim

Not As S

pecif

ied

Raw E

dge Se

am

Cons

t. No

t As S

pecif

ied

Open Se

am

Unev

en S

t.

Puck

ering

Skip

St.

Brok

en St.

2500

2000

1500

1000

500

0

100

80

60

40

20

0

Pareto Chart of Fault Desc.

The 80–20 theory was first developed in 1906, by Italian economist, Vilferdo Pareto, who observed an unequal distribution of wealth and power in a relatively small proportion of the total population.

Joseph M. Juran is credited with adapting Pareto’s economic observations to business applications.

Separates the "vital few" from the "trivial many" (Pareto Principle)

PARETO ANALYSIS (Cont…)

The 80:20 Rule Examples:

80% of your phone calls go to 20% of the

names of your list

20% of the roads handle 80% of the traffic

80% of the meals in a restaurant come from

20% of the menu

20% of the people causes 80% of the

problems

PARETO ANALYSIS (Cont…) Pareto Chart Using Minitab– EXAMPLE:

Suppose you work for a company that manufactures motorcycles. You hope to reduce quality costs arising from defective speedometers. During inspection, a certain number of speedometers are rejected, and the types of defects recorded. You enter the name of the defect into a worksheet column called Defects, and the corresponding counts into a column called Counts. You know that you can save the most money by focusing on the defects responsible for most of the rejections. A Pareto chart will help you identify which defects are causing most of your problems.

Open the worksheet EXH_QC.MTW

PARETO ANALYSIS (Cont…) Pareto Chart Using Minitab– EXAMPLE:

EXH_QC.MTW (Cont…) Step – 1:

Choose Stat Quality Tools Pareto Chart

Step – 2:

Choose Chart defects table. In Labels in, enter a column

of Defects. In Frequencies in, enter a

column of Counts

PARETO ANALYSIS (Cont…) Pareto Chart Using Minitab– EXAMPLE:

EXH_QC.MTW (Cont…)

PARETO ANALYSIS (Cont…) Pareto Chart Using Minitab– EXAMPLE:

EXH_QC.MTW (Cont…)

Analyze the Chart:Focus on improving the number of missing screws because over half of your speedometers are rejected due to this defect.

SIPOC DIAGRAM (Cont…)The figure below shows the linkage of the SIPOC to future tools used in the DMAIC process:

OVERVIEW OF THE BRAINSTORMING

TECHNIQUESA commonly used tool to seek ideas by using categories to stimulates causes and effect relationship with a problem. It uses verbal inputs in a team environment.

The “Y”The

“Problem”The “X’s”“Causes”

Categories

CAUSE & EFFECT DIAGRAM Cause-and-Effect Diagram (also

known as a "Fishbone Diagram") is a graphical technique for grouping people's ideas about the causes of a problem.

Invented by Professor Kaoru Ishikawa of Tokyo University; Japanese expert in quality management.

PRODUCTS1. Measuremen

t2. People3. Method4. Materials5. Equipment6. Environment

Categories for the legs of the diagram can use templates for products or transactional symptoms. Or you can select the categories by process step or what you think appropriate for the situation.

TRANSACTIONAL1. People2. Policy3. Procedure4. Place5. Measurement6. Environment

CAUSE & EFFECT DIAGRAM (Cont…)CLASSIFYING THE X’s

The CAUSE & EFFECT DIAGRAM is simply a tool to generate opinions about possible causes for defects.For each of the X’s identified in the Fishbone diagram classify them as follows:

Controllable – C (Knowledge) Procedural – P (People, System) Noise – N (External or Uncontrollable)

Think of procedural as a subset of controllable. Unfortunately, many procedures within a company are not well controlled and can cause the defect level to go up. The classification methodology is used to separate the X’s so they can be used in the X–Y (Correlation or Cause & Effect) Matrix and the FMEA taught later.WHICH X’s CAUSE

DEFECTS?

C & E DIAGRAM USING MINITAB EXAMPLE:

Using a Pareto Chart, You discovered that your parts were rejected most often due to surface flaws. This afternoon, You are meeting with members of various departments to brainstorm potential causes for these flaws. Beforehand, you decide to print a cause & Effect (Fishbone) diagram to help organize your notes during the meeting. The example below illustrates how to generate a complete Cause & Effect diagram with sub–branches.

OPEN THE FILE: SURFACEFLAWS.MTW

C & E DIAGRAM USING MINITAB

C & E DIAGRAM USING MINITAB

C & E DIAGRAM USING MINITAB

DEFINITION OF X–Y MATRIX

The (X–Y) CAUSE & EFFECT Matrix is: A tool used to identify potential X’s and assess

their relative impact on multiple Y’s (including all Y’s that are customer focused)

Based on the team’s collective “opinions” Created for every project Updated whenever a parameter is changed

To summarize, the X–Y is a team based prioritization tool for the potential X’s

WARNING! This is not real data, this is organized brainstorming!! At the conclusion of the project you may realize that the things you thought were critical are in fact not as important as was believed.

THE X–Y MATRIX (Cont…)THE VITAL FEW:

A Six Sigma Belt does not just discover which X’s are important in a process (the Vital few).The team considers all possible X’s that can contribute or cause the problem observed.

The team uses three primary sources of ‘X’ identification: 1. Process Mapping2. Fishbone Analysis3. Basic Data Analysis – Graphical and Statistical

A List of X’s is established and compiled.The team then prioritizes which X’s it will explore first, and eliminates the “obvious” low impact X’s from further consideration.

The X–Y Matrix is this Prioritization Tool!

THE X–Y MATRIX (Cont…)PROCEDURE FOR MAKING AN X-Y MATRIX:

1. List out the CTQ (Y’s) for the targeted process.

2. Make a table with numbers of rows and columns.

3. Write down the CTQ against individual column.

4. Write the weight-age for each CTQ.

5. Find out input process parameters (X’s) by

brainstorming and write them against individual

rows.

6. Put suitable numbers in the intersection of rows and

columns to show the relationship between X’s and

Y’s.

7. Finally calculate the weighted sum against each X’s.

THE X–Y MATRIX (Cont…)EXAMPLE: Let’s take the example of the newspaper printing process. After transforming the VOC we find the CTQ (Y’s) as below:

Clearly readable print Good quality photo Harmless to health

Upon brainstorming, the input process parameters (X’s) have been found as below: Good quality ink Less vibration during operation of printing press Paper quality

For the above sets of X’s and Y’s the X-Y matrix table will look like the example below:

Wherever there is a strong relation between X’s and Y’s, put 9. For weak relations put 3 or 1. Keep the intersection field blank if there is significant relation.

Weighted sum for “Good quality ink” is calculated as 15*9 + 10*9 + 10*1 = 235.

The calculation is similar for the rest of the X’s. The input parameters with a higher weighted sum should be selected for further FMEA.

QUESTIONS

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