q-book
Quality Tools
Quick Reference Guide
VOP/DQA
November, 2011
Version 2.0/ Revision 1
Approval Sheet
Prepared by:
Frederico Cardoso Della Bidia - Quality Engineer
Revision:
Giovanni José Rosa - Quality Manager
Approval:
Alexandre Braz Negroni - Senior Manager, Supplier Quality
and Development
Nilson Jair Santin - VP Product Quality
Index
Introduction
4
The 7 “old” Tools
5
Pareto Chart
6
Ishikawa Diagram
8
Histogram
10
Control Charts
12
Scatter Plot
14
Flowchart
16
Check Sheet
18
The 7 “new” Tools
21
Affinity Diagram
22
Relations Diagram
24
Tree Diagram
26
QFD – Quality Function Deployment
28
01
Index
02
Decision Matrix
30
Process Decision Program Chart
32
Arrow Diagram
34
Advanced Tools
37
DOE (Design Of Experiments)
38
FMEA (Failure Mode and Effect Analysis)
40
SPC (Statistical Process Control)
42
MSA (Measurement System Analysis)
44
Waterfall Chart
46
A3
48
ARCA (Apollo Root Cause Analysis)
50
KC (Key Characteristic)
52
Poka-Yoke
54
Problem Solving Technique
56
Index
GUT
58
Brainstorming
60
5W1H
62
REFERENCES:
•ASQ website - http://asq.org/learn-about-quality/data-collection-analysistools/overview/check-sheet.html;
•Wikipedia - http://en.wikipedia.org/wiki/Check_sheet;
•http://www.coe.montana.edu/ie/faculty/sobek/a3/index.htm);
•http://www.sccs.swarthmore.edu/users/06/adem/engin/excel/waterfall_ch
art/index.php;
•Wikipedia: (http://en.wikipedia.org/wiki/Waterfall_chart);
•ENS-000604 “Quality Tools Guide”;
•ENS-002154 “System Measurement Analysis”.
•NE 01-120, ENS-000344 – “Variation Management”;
•”Análise de Problemas e Tomada de Decisão”, TSG Consulting;
•http://thequalityportal.com/pokayoke.htm;
•Wikipedia - http://en.wikipedia.org/wiki/Poka-yoke;
•http://www.apollorca.com
03
Introduction
This guide aims to provide a quick and direct reference to the
Quality Tools used by EMBRAER on its production system.
As a reference only, each topic is described in a succinct mode
but enough to excel the use of the tools. It also allows
comparison in order to ensure the use of the appropriate tool
for each problem.
The development of this guide was structured in a way to
achieve the desired purposes. Each tool comes with the
necessary information for its use, a brief description, and a
sample chart. External references are described including
EMBRAER’s technical standards to allow the access to
additional information on the subject.
Enjoy the reading!
04
The 7 “Old”
Old” Tools
The 7 “old” tools or 7 “quality control tools” groups the first tools
used to solve quality problems in the industry.
These tools are primarily reactive or corrective to the issues.
Those are:
• Pareto Chart;
• Ishikawa Diagram (also 6 M’s or Fishbone);
• Histogram;
• Control Charts;
• Scatter Plot;
• Flowchart;
• Check Sheet.
05
Pareto Chart
SCOPE: Prioritize the necessary actions to solve a problem.
DESCRIPTION: It’s a bar chart that helps on the prioritization of the
actions by sorting out all the elements according to its incidence
level. The purpose is to highlight the most important among a
(typically large) set of problems. Sorting the “few vitals from the
trivial”. As a general rule, 80% of the problems are included on 20%
of the total of raised items.
The bars are on a decreasing order, and show the cumulative
percentage of the total number of occurrences in order to highlight
the most significant ones.
The cumulative total is represented by a line, with the last item
reaching 100%. That allows us to point out the major problems out of
the total, helping with the prioritization of the actions.
06
Example
07
Ishikawa Diagram
SCOPE: Diagram that shows the causes and effects of a certain
event. It’s a tool that helps finding the key characteristics and
parameters of the process.
DESCRIPTION: Each cause or reason for imperfection is a
source of variation. Causes are grouped into major categories to
identify these sources of variation.
It represents the relationship of how an effect is influenced by its
causes.
It is also known as cause-and-effect diagram, or the 6Ms of the
process. It groups the possible causes in 6 categories as follows:
• Machine;
• Material;
• Man Power;
• Method;
• Mother Nature;
• Measurement.
08
09
EXAMPLE:
HISTOGRAM
SCOPE: Allows a quick overview of the distribution of a variable
in a large number of data.
DESCRIPTION: It is a bar chart that shows the variations of a
certain process. It is also known as “Frequency Distribution”
because it gives the frequency densities of observations in an
interval as the height of each bar. In order to prepare an
histogram, it’s necessary to categorize each interval of
observation. The number of categories depends on the total
amount of observations made as shown below:
10
11
EXAMPLE:
Control Charts
SCOPE: To determine whether or not a manufacturing process is
under statistical control, with variation only coming from sources
common to the process .
DESCRIPTION: A control chart consists of a center line that is
drawn at the value of the mean of the statistic, Upper and Lower
Control limits (sometimes called "natural process limits"), and
points representing a statistic of measurements of a quality
characteristic in samples taken from the process at different
times.
When used alone, a control chart represents a reactive method.
When used in a Statistical Process Control context (see SPC
section of this guide) it works preventively.
12
13
EXAMPLE:
Scatter Plot
SCOPE: To test types of correlations between variables (cause
and effect) with a certain confidence interval.
DESCRIPTION: This type of plot is also known as scatter
diagram or scatter graph. It’s a graphic tool that illustrates the
degree of correlation between two variables.
14
15
EXAMPLE:
FLOWCHART
SCOPE: To show the connection between customers and
suppliers.
DESCRIPTION: It’s a diagrammatic representation of process
operations and their order by connecting those.
16
17
EXAMPLE:
CHECK SHEET
SCOPE: To collect data in real-time and at the location where
the data is generated.
DESCRIPTION: It is also known as “tally sheet”. It records data
by making marks on specific planned forms. The data is read by
observing the location and number of marks on the sheet.
There are 4 types of check sheets:
• Manufacturing Process Distribution;
• Classification: of the deffective item in categories;
• Location: that the defect is physically located ;
• Defect Causes;
18
19
EXAMPLE:
BLANK PAGE
20
The 7 “New”
New” Tools
The 7 “new” tools or 7 “quality management planning tools” are
considered an evolution from the 7 “old” tools since those allow
detailed planning as a preventive character.
The “New” tools are:
•Affinity Diagram
•Relations Diagram
•Tree Diagram
•QFD – Quality Function Deployment
•Decision Matrix
•Process Decision Program Chart
•Arrow Diagram
21
Affinity Diagram
SCOPE: Organizes a large number of ideas into their natural
relationships.
DESCRIPTION: It’s a diagram that groups a large number of
ideas or opinions showing how those correlate.
22
23
EXAMPLE:
Relations Diagram
SCOPE: To identify the absolute cause.
DESCRIPTION: shows cause-and-effect relationships and helps
you analyze the natural links between different aspects of a
complex situation.
24
25
EXAMPLE:
TREE DIAGRAM
SCOPE: Breaks down broad categories into finer and finer levels
of detail, helping you move your thinking step by step from
generalities to specifics.
DESCRIPTION: The tree diagram starts with one item that
branches into two or more, each of which branch into two or
more, and so on aiming a goal. It looks like a tree, with trunk and
multiple branches.
26
27
EXAMPLE
QFD - QUALITY FUNCTION DEPLOYMENT
SCOPE: To transform customer demands into design quality,
prioritizing them, to deploy the functions forming quality, and to
deploy methods for achieving the design quality into subsystems
and component parts, and ultimately to specific elements of the
manufacturing process.
DESCRIPTION: It’s a graphic illustration of the correlation
among several factors from two or more groups.
It helps to transform the voice of the customer into engineering
characteristics (and appropriate test methods) for a product or
service.
28
29
EXAMPLE:
DECISION MATRIX
SCOPE: To use pair wise comparisons of a list of possible
solutions to a set of criteria in order to choose the best solution.
DESCRIPTION: The prioritization matrix, also know as the
criteria matrix, is used to compare choices relative to criteria in
order to find the best applicable solution.
A particular way of prioritizing is using the “GUT” technique that
prioritizes solutions by Gravity, Urgency, and Tendency.
30
31
EXAMPLE:
PROC. DECISION PROGRAM CHART
SCOPE: Systematically identifies what might go wrong in a plan
under development. It helps choosing the best alternative.
DESCRIPTION: The process decision program chart
systematically identifies what might go wrong in a plan under
development. Countermeasures are developed to prevent or
offset those problems. By using PDPC, you can either revise the
plan to avoid the problems or be prepared with the best response
when a problem occurs.
Some questions that can be used to identify problems:
- What assumptions are we making that could turn out to be
wrong?
- Have we allowed any margin for error?
32
33
EXAMPLE:
ARROW DIAGRAM
SCOPE: To show the required order of tasks in a project or
process, the best schedule for the entire project, and potential
scheduling and resource problems and their solutions.
DESCRIPTION: The arrow diagram shows the required order of
tasks in a project or process, the best schedule for the entire
project, and potential scheduling and resource problems and
their solutions. The arrow diagram lets you calculate the “critical
path” of the project.
The two types of arrow diagrams most used are : PERT
(Program Evaluation and Review Technique) and GANTT
CHART.
34
35
PERT
Gantt
EXAMPLE:
BLANK PAGE
36
Advanced Tools
Some other important Quality tools that are not part of the two
groups previously described (7 Old and 7 New Quality Tools)
are:
• DOE;
• FMEA;
• SPC;
• MSA;
•Waterfall Chart;
• A3;
• ARCA;
• KC;
• Poka-Yoke
• Problem Solving Technique;
• GUT;
• Brainstorming;
• 5W1H.
37
DOE
SCOPE: “Design Of Experiments”, is a process that aims the
optimization of a process.
DESCRIPTION: DOE is a statistical tool that points out the main
factors/features that have the most significant contribution for the
result of a process, so that the condition of those factors that
provides the best result might be determined.
It is used mainly with processes with a large number of input
variables.
It allows simultaneous variation of all variables over the
experiments, measuring the impact of each one at the final
result.
This tool might be used to reduce the necessary number of
experiments, allowing savings on a experimental process.
Nowadays, there are some softwares that automate the process,
issuing the experimental matrix and compiling the data for
statistical control.
38
EXAMPLE:
Experimental Matrix
Response Surface
39
FMEA
SCOPE: Failure Mode and Effect Analysis is a procedure in
product development and operations management for analysis of
potential failure modes within a system for classification by the
severity and likelihood of the failures.
DESCRIPTION: There are two types of FMEA: the “Design
FMEA” (DFMEA) and the “Process FMEA” (PFMEA);
A successful FMEA activity helps a team to identify potential
failure modes based on past experience with similar products or
processes, enabling the team to design those failures out of the
system with the minimum of effort and resource expenditure,
thereby reducing development time and costs. It is widely used in
manufacturing industries in various phases of the product life
cycle and is now increasingly finding use in the service industry.
It is recommended that the FMEA to be used by multifunctional
teams.
It rates the failure modes for severity, occurence, and detection.
40
41
EXAMPLE:
SPC
SCOPE: Is the application of statistical methods to monitor and
control a process to ensure that it operates at its full potential to
produce conforming product.
DESCRIPTION: It examines a process over the time and the
sources of variation in that process by using tools that give
weight to objective analysis over subjective opinions and that
allow the strength of each source to be determined numerically.
Variations in the process that may affect the quality of the end
product or service might be detected and corrected, thus
reducing waste as well as the likelihood that problems will be
passed onto the customer.
It measures variables or attributes of a process and registers that
on control charts, compiling the statistical data in order to allow
the appropriate decision to be taken in the process.
The measurements are made with maximum and minimum
values as references, that are usually defined as Upper and
Lower control limits based on an Engineering specification.
Depending on the production volume, statistical sampling might
be used in order to save time with the process.
42
43
EXAMPLE:
MSA
SCOPE: Measurement System Analysis is a specially designed
experiment that seeks to identify the elements of variation in the
measurement. It aims to ensure the accuracy of a measurement
system/equipment.
DESCRIPTION: It evaluates the test method, measuring
instruments, and the entire process of obtaining measurements
to ensure the integrity of data used for analysis (usually quality
analysis) and to understand the implications of measurement
error for decisions made about a product or process. MSA
analyzes the collection of equipment, operations, procedures,
software and personnel that affects a measurement
characteristic. The result of that analysis is a rate known as R&R
(Repeatability and Reproducibility).
The measurement equipment might also be analyzed for:
• Stability;
• Tendency;
• Linearity.
MSA includes many different techniques, and the R&R is one of
the most used.
44
45
EXAMPLE:
WATERFALL CHART
SCOPE: To visualize cumulative data.
DESCRIPTION: It’s a form of data visualization which helps in
determining the cumulative effect of sequentially introduced
positive or negative values.
The waterfall chart is normally used for understanding how an
initial value is affected by a series of intermediate positive or
negative values. Usually the initial and the final values are
represented by whole columns, while the intermediate values are
denoted by floating columns. The columns are color coded for
distinguishing between positive and negative values.
It’s very often used as a tool for financial analysis and stock
control.
It is also used in order to forecast the impact of different actions
aiming a planned goal.
46
47
80%
82%
84%
86%
88%
90%
92%
94%
96%
98%
100%
Sep-09
actual
89.0
Oct-09
0,0%
Nov-09
0,0%
3,00%
Jan-10
Action#1 to
improve the
AR
Dec-09
0,0%
EXAMPLE:
Feb-10
Action#2
to improve
the AR
3,0%
Mar-10
Apr-10
Action#3 to
improve the
AR
4,0%
May-10
Jun-10
Action#4 to
improve the
AR
0,7%
Supplier Acceptance Rate at Embraer
PN XXXXX - PN Description: XXXXX - Waterfall Chart
Jul-10
Aug-10
99,90%
Goal
Acceptance Rate
A3
SCOPE: Project Management.
DESCRIPTION: The A3 report is a tool that proposes solutions
to problems, give status reports on ongoing projects, and report
results of information gathering activity.
The name “A3” refers to the paper sheet size used with this tool
(limiting the maximum area to be used). All relevant information
must be filled in the A3 report.
It’s a summary that might have a lay-out, type, and emphasis
adapted as necessary.
The elements that are part of an A3, those follow a natural and
logic sequence. The problem, the root-cause, the goal, and the
actions suggested to reach that goal must be clear enough for an
easy comprehension.
It’s a tool used for decision making, planning, proposals, problem
resolution, etc;
Each purpose for the use of the tool requires an specific format,
of which there is no standard one.
48
49
EXAMPLE:
ARCA
SCOPE: “Apollo Root Cause Analysis” - It aims the discovery of
the root-cause of a problem and the implementation of a counter
measure.
DESCRIPTION: This method is similar to the Tree Diagram, but
with a qualitative emphasis.
It starts by the identification of the effect of which the root-cause
is required to be found.
Every effect is caused by the sum of an action and a condition.
CONDITION: represents a cause that already exists before na
action;
ACTION: represents a momentarily cause that links the “effect”
with the “condition”.
This methodology work is based on the evidence of the
conditions and actions found to uphold the response to the
problem.
The analysis is finished when there are no more actions and
effects or when those no longer make sense.
50
51
EXAMPLE:
KC
SCOPE: “Key Characteristic” - To control critical elements in a
manufacturing process.
DESCRIPTION: A Key Characteristic of an individual part, an
assembly, or a system is a geometric attribute, functional, or
cosmetic, that is also measurable and which dimensional control
is necessary in order to comply with customer requirements.
The definition of Key Characteristics might be done by the use of
other quality tools such as FMEA or QFD.
After the identification of these Key Characteristics, a Control
Plan needs to be formulated in order to provide process
monitoring.
After the implementation of the Control Plan, the monitoring and
management of Key Characteristics follows the standard SPC
method.
52
53
EXAMPLE:
Poka -Yoke
SCOPE: It’s a Japanese term that means "fail-safing" or "mistakeproofing". A poka-yoke is any mechanism in a lean manufacturing
process that helps an equipment operator avoid (yokeru) mistakes (poka).
DESCRIPTION: Its purpose is to eliminate product defects by preventing,
correcting, or drawing attention to human errors as they occur. The
concept was formalized, and the term adopted, by Shigeo Shingo as part
of the Toyota Production System.
Either the operator is alerted when a mistake is about to be made, or the
poka-yoke device actually prevents the mistake from being made. the
former would be called a “Warning” poka-yoke (i.e.: bliking lights), while
the latter would be referred to as a “Control” poka-yoke.
There are three types of poka-yoke for detecting and preventing errors:
•The Contact method identifies product defects by testing the product's
shape, size, color, or other physical attributes.
•The Fixed-Value (or constant number) method alerts the operator if a
certain number of movements are not made.
•The Motion-Step (or sequence) method determines whether the
prescribed steps of the process have been followed.
54
55
EXAMPLE:
PROBLEM SOLVING TECHNIQUE
SCOPE: To solve problems through a planned technique.
DESCRIPTION: A problem solving technique has the following
steps:
• Problem Identification (clear definition);
• Temporary countermeasure Implementation (in order to ensure
a continuous process flow);
• Problem Observation (investigation of problem main
characteristics);
• Problem Analysis (finding out the key causes);
• Permanent Corrective Action Definition and Implementation
(use of the most efficient corrective action);
• Verification (if the problem persists);
• Standardization (to avoid new incidences);
• Conclusion.
56
Problem
Identification
EXAMPLE:
Temporary
Counter-measure
Implementation
Problem
Observation
Solution
Definition and
Implementation
Verification
Effective
Solution?
YES
Problem
Analysis
Standardization
Conclusion
57
GUT
SCOPE: To establish priorities in problems, allowing the
definition of the most relevant.
DESCRIPTION: This tool prioritizes problems according to the
following criteria:
• Gravity: harm level caused by the problem (material – moral –
financial);
• Urgency: it correlates the problem with the solution ease (solve
what is easier);
• Risk: it analyses the problem progress in case no action is
taken to solve it
Each of the criteria above might be rated by (or other equivalent):
(H) High, (M) Medium, or (L) Low.
58
59
EXAMPLE:
Brainstorming
SCOPE: To raise ideas as much as possible in a team for many
different purposes.
DESCRIPTION: Brainstorming follows these steps:
• Definition: To understand the scope, making sure that all the
team members understand it;
• Brainstorming: Quality team members shall present their ideas,
each one in a sequence;
• Record: To record all suggestions as those were presented.
•Clarifying: The team needs to clarify any item or idea that is not
clear enough;
• Selection: Team members shall in common agreement define
the most relevant items;
60
Definição
Definition
EXAMPLE:
Brainstroming
Registro
Record
Esclarecimento
Clarifying
Solução
Solution
61
5W1H
SCOPE: To define the operational standards and action plans.
DESCRIPTION: The 5W1H is used by answering the following
questions for each process item or action plan:
What
- What is this task?
Who
- Who should carry on with this task?
- What needs to be done?
- Who is responsible?
Where
- Where the task should be conducted?
- Where (place)?
When
- When does this task needs to be conducted?
Why
- Why does this task needs to be done?
- When (time)?
How
- How to conduct this task?
- How (method)?
62
63
EXAMPLE: