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Transcript of root cause analysis
Intelux Electronics Private Ltd
Presentation- Root Cause Analysis
By
Mr. Sandip Tambe
Quality Assurance
Intelux Electronics Pvt. Ltd
Scope
• To Understand ISO 9001 requirements on cause non conformities, cause identification, correction & corrective action.
• To Apply these requirements in generating non conformities, planning & implementing corrective actions.
• To Review non conformities, correction,causes & corrective action reporting for correctness.
• Improve effectiveness of QMS by effective implementation of corrective actions
“Every Problem is an opportunity”
“Every defect is treasure ,if the company can uncover its cause and work to prevent it across the corporation”
- Kilchiro Toyoda, founder of Toyota
.
• ISO 900 Requirements Vis-à-vis
Root Cause Analysis
What is a Nonconformance ?
ISO 9000:2000, 3.6.2“Non – Fulfillment of a Requirement”
• Objective evidence exists showing that:
• Type of NC - • A requirement not been addressed (intent)• Practice differs from the defined system(implementation)• The practice is not effective (effectiveness)
• Correction: Action to eliminate a detected non conformity
Defect and Non conformity
• Defect –
Non fulfillment of requirement related to an intended or specified use
Product quality characteristics
• Non conformity :
Non fulfillment of requirement
Business or production process
Corrective x Preventive action
• Corrective Action –• Action to eliminate
cause of detected non conformity or other undesirable situation
• Preventive Action –• Action to eliminate the
cause of a potential non conformity
ISO 9001 Requirement
• Internal Audit – 8.2.2• Documented Procedure
• Audit Planning
• Roles of Auditor & Auditee
• Correction &Corrective Action
• Records of Results of Audit
• Corrective Action – 8.5.2• Documented Procedure• Identification of Non conformity• Identification of cause• Elimination of cause• Plan and implementation of
corrective action• Review of effectiveness• Maintain record
Nonconformity Report
No set rules; however all have these two parts:
• The requirement ( What was supposed to do ) • The evidence ( What actually is )• • Different organizations have different formats
• Use the format chosen by your client or firm.
• Non conformance must be, Factual, Precise, Objective, Traceable, Concise
Examples of NCs & CAs
• Scenario:• Production- Lens Department W-4• Morning Shift.• 4 out of 18 operators seen not wearing nylon caps. Caps
were available at the entrance area.• WI4-01, Clause 6, requires that all personnel entering W-
4 must wear nylon caps. Instruction clearly displayed at the entrance.
.
• Area • Problem• Attribution• Grading• Reference to internal • Requirement's), if
Necessary• Sign
IRCA Quality Audit Incident No…………... NONCONFORMITY REPORT
Company Under Audit XYZ plc. Note Number………
Area Under Review. ISO9001 Class No………...
Production- Lens.Div.W-4…………………..6.4.
Category: Major/Minor
Deficiency: During the morning shift 4 out of 18 operators were not wearing nylon caps.W14-01, cl, 6, requires that all staff entering W-4 must wear nylon caps.The Slandered requires that the organization must determine & manage the work environment needed to achieve product conformity.
Auditor :Yogita
Corrective Action Proposed:
• The 4 concerned operators will be given a verbal warning to follow system.
• Will the proposed action prevent recurrence of the non conformity?
• New operator - training
Quality Tools for Root Cause Analysis
What is Root cause Analysis?
• A process designed for use in investigating & categorizing the root cause of events with safety, health, environmental, quality, reliability & production impacts.
• Simply stated RCA is a tool designed to help identify not only what & how an event occurred, but also why it happened.
• Should we apply in depth root cause analysis for each identified non conformity or problem ?
Major steps in RCA:• Step1 – Problem identification
• Steip2 – Data collection
• Step3 – Causal factor charting
• Step4 –Root Cause Identification
• Step5 – Corrective action Recommendations & Implementation
Tools & Techniques:
• Brain Storming• Data Collection• Graphs & Charts• Flow Charts (process Map)• Pareto Analysis• Histogram• Cause & Effect Diagram• Scatter Diagram
Brain Storming
• Brain Storming is used to establish common method for a team to creatively & Efficiently generate high volume of ideas on any topic
• Brainstorming encourages of all the team members without the dominance of anyone team member
• Allows team members to build on each others creativity while staying focus on the joint mission
.
• Definition – Brain Storming is a team approach to generate creative in a short time brain storming plays an important role to build a cause & Effect diagram.
• Why Brain Storming? • To identify the problem
• To identify critical causes• To find the Solution
• To Prevent the problem
Types of Brainstorming -
• Free Wheeling: Spontaneous flow of ideas by all team members
• Round Robin: Team members take turns suggesting ideas
• Card Method: Team members write ideas on cards with no discussion
Brain storming :
Structured• Every person in a group must give an idea as their turn• Forces even shy people to participate.• Create a certain amount of press
Unstructured• Group members simply give ideas as they come to mind • Create more relaxed atmosphere• Risks domination.• Thumb rule: 5-15 minutes works well
Data Collection
• “The Skill with which a company collects & uses data can make the difference between success & failure”
-Maasaki Imai
Data Collection
• Step1 : What is data?
• Data is information about a topic
• It is derived from objects, situations or phenomenon in the form of measurements.
• It is used to classify, describe, improve or control objects, situations or phenomenon.
Plan for the Data Collection
How to measure the data ?
Establish Data
Collection Goals
Develop operational Definitions
& procedures/ measurement
method
Ensure Data consistency &
Stability
Collect Data & Monitor
Consistency
•Clarity Purpose of data collection
•Identify what data to collect
•Write & pilot operational definitions
•Develop & pilot data collection forms & Procedures
•Establish a sampling
• Test & Validate measurement systems
•Train data collectors
•Pilot process & make Adjustments
•Collect data
•Monitor data accuracy & consistency
•Data collection is the 1st step to Understanding the Variation the Customer Feels
Types of Data:• Data type is an important considerations because it can
impact not only hoe you define your measures but also how you collect data & what you can learn from it.
• Discrete Data (Attribute data)
• Discrete data is information that can be categorized into a classification. It is based on counts.
• Finite no. Of values which can not be subdivided meaningfully.
• Binary (Yes/No, Defect/No Defect)
• Ordered categories( 1-5)• E.g. No. of incomplete
applications– No. of Green Belts
Trained
Continuous Data (Variable Data)
• Continuous data is information that can be measured on a continuous & Scale.
• Can have almost any number value which can be measuring subdivided into finer & finer increments
• Can be broken down into increments
• Infinite no. of possible values E.g.Cycle time (measured in days, hour, minutes, etc.)
Weight (measured in tons,pounds,etc.)
Pros & Cons – Discrete Data
Pros:• Factors can be defined only as
discrete data,
e.g. –Location (State, City, Street), Customer type new or repeat, business VS home)
• Intangible factors can often be converted into measurable discreet characteristics, E.g. Effectiveness of ad (good, bad, not sure)
• It is faster & easier to capture discrete data
• Cons:• Requires to make more
observations to get valid information. Need to count more items to get accurate data. some statisticians note that continuous data can be accurate with a sample of just 200 items no matter how high the volume of the process. So discrete data can be more expensive
• Discrete data can bury important information
• You can do many more potentially useful Analysis with continuous data versus discrete
Key Concepts- Defects Based Measurement
• Unit- an items being processed, or the final product or service being delivered to the customer- a car, a hotel statement etc. Defect- a failure tom meet a customer requirement or performance standard – a leaky cranky case, a lost reservation
• Defective- any unit that contains one or more defects. Hence a car with any defects is just defective as a car with 15 defects
• Opportunity – a chance to go right or wrong- Most product or services have multiple customer requirements, there can be several chances or opportunities to have a defect
.Graph
Purpose:
• Graphs & Charts are pictorial representation of the data, making it easy to spot trends, ratios & comparisons among different groups of data.
.
• The more common types of graphs & charts are line graphs ,Bar charts & pie charts.
• To present the numerical Data in an easy to plot visual form.
Graph
• To present the numerical Data in an easy to plot visual form.
• Line graphs used to depict change or variation over time
• Bar charts are used for comparing quantities between persons, regions, time intervals etc.
• Pie Charts are used to show % or proportions of different components of a specific items.
• Select the type of chart or graph most suitable for the type of data.
• Decide the units & scale of items to be shown on X-axis & Y-axis.
• Fill the information on the graph sheet.• Join the required points to complete line or bars.• Colour or shade the lines or bars to distinguish between
different groups or classes.• Provide appropriate title.
Response Time
96
1
9297
96 94
100
9595
100 95
0
20
40
60
80
100
Week 43 Week 44 Week 45 Week 46 Week 47
% C
om
plit
ion
Line Graph - Example
Bar Graph - Example
INWARD VOLUME - Oct. 2009
020406080
100120
Week 42 Week 43 Week 44 Week 45 WeeK 46 Week 47
Type
JSRV/SRV VOLUME
Week 42 Week 43 Week 44 Week 45 WeeK 46 Week 47
SRV 48 75 46 76 82 63
JSRV 86 60 79 75 112 68
Total 134 135 125 151 194 131
Pie Chart - Example
26%
13%
41%
3%0%17%
WP
WI
JUMP
DRY
MISSING
OTHER
Monthwise SRV RejMonth No. of Items
Month Inspected Rejected
Jan-09 414 7
Feb-09 39 17
Mar-09 572 23
Apr-09 387 27
May-09 562 32
Jun-09 499 26
Jul-09 822 31
Aug-09 438 31
Monthwise SRV Rej
0
200
400
600
800
1000
Jan-09
Feb-09
Mar-09
Apr-09
May-09
Jun-09
Jul-09 Aug-09
Month
Inspected
Rejected
Process Mapping
• Process mapping is technique used for marking work visible
• Process map shows who is doing what ,with whom ,when and for how long
• It also shows decision that are made , sequence of events and time delays, if any in the process
Step1Start
Step 2A Step 2B Step2C
Step3
ReworkEndGood
NO Yes
Process flow diagram that visualizes how work is done.
Symbol Meaning
Start or End of Process
Activity or Process
Decision or Inspection point
Connector
Direction of flow
Process mapping Steps
• 1.Fix process start & end points• 2.Brainstorms list of process steps.• 3.Do first walk-through & interview• 4.List key process steps on sticky notes• 5.Discuss, review & modify• 6.Do second walk-through & interview• 7.Add inspection, rework, repair and scrap steps
on sticky notes• 8.Agree on “as is” process map.
Processes Mapping -
• Start And End Point -• Review problem statement• Describe the process causing the problem• Discuss measurable start & end points• Agree & record• Problem statement :• Customer waits to long for modified drawings.• Process:• Drawing revision process.• Ask:• - what might the start point be?• Ask:• - what might the end point be?
Process Map - Analysis
Identify : Process deliverablesProcess outputValue added and non value added stepsIntermediate measuresInput and output for key process stepsSpecific types of wastes in each step
Process Mapping :analysis
A. Look at each process for
Bottle necks Sources of delay Errors being fixed instead of being prevented Role ambiguity Duplications Unnecessary steps Cycle time
B. Look at each decision for Authority ambiguity Are the decision needed for this point
Process Mapping :analysis
C. Look at each Rework loop for
Possibly doing it in less time Possibility of eliminating step Trying to prevent
D. Using Customer Point of View Identify value added vs non value added steps
What Is A Pareto Diagram?
• A diagram that shows 20% of the input(Xs) Of the problems with dependent process outputs(Ys)
KEEP IN MIND-
Pareto analysis is powerful tool when we use objective data & facts & not opinions.
Pareto Analysis
• Vilfredo pareto was an Italian engineer in the 19th century who studied the number of people in various income classes & declared…
• - 20% of the people own 80% of the country’s wealth.• - 80% of the people own 20% of the country’s wealth.• - Get the biggest problem first • - Solve the vital Few• Remember…• The most frequent or most costly events are not always the most
important• e.g.• Two fatal accidents deserve more attention than 100 cut fingers.
Steps to Build a Pareto Chart
• 1. Arrange data in the descending order
• 2. Collect Data• 3. Calculate the cumulative in the next
column• 4. Calculate cumulative % in the next
column• 5. Draw a graph with scales on both
axis• 6. Draw bar chart based on data• 7.Using cumulative data, draw
cumulative curve• 8.Identify the VITAL FEW
• Exercise -
Players Runs
Laxman 281
Dravid 180
Ganguli 48
SS Das 39
S Ramesh 30
Zaheer Khan 23
Sachin 10
Mongia 4
Players ScoredPlayers Runs Cum %
Laxman 281 281 45
Dravid 180 461 73
Ganguli 48 509 81
SS Das 39 548 87
S Ramesh 30 578 92
Zaheer Khan 23 601 96
Sachin 10 611 98
Harbhajan 8 619 99
Mongia 4 623 100
0
20
40
60
80
100
120
Laxm
an
Dravid
Gangu
li
SS Das
S Ram
esh
Zaheer
Kha
n
Sachin
Harbha
jan
Mon
gia
% r
un
%
What is cause
• CAUSE = Reason or Factor contributing to the EFFECT CAUSE is happens.
• In 1953,Kaoru Ishikawa, Professor of the University of Tokyo, used the cause & effect diagram for the first time.
• A cause & effect diagram is also called a fish bone diagram since it looks like the skeleton of a fish.
• If there are no clues to indicate the cause, Write a cause & effect diagram.
• List down the possible & probable causes by brain storming.• Group them under 5M & E category• Then by observation eliminate causes which do not
contribute to the problem.
Cause Effect
Material Machine Environment
Measurement Man Method
Fishbone Diagram
• Arial Font Size 24
• Cause & Effect Diagramming is brainstorming!• It is very important to ask “WHY” over &over again. Good
cause & Effect Diagramming is question & answer.• Teams create cause & effect diagrams to get at the
difficult to discover causes.
People
Poor & declining participation I improvement
programs
People resist change
1.1They fear making mistakes
(1.1.1)They are criticized for mistakes
(1.1.2) They are penalized for mistakes
(1.1.3)To err is human to forgive is not company policy
1.2 They fear job loss
Why, Why , Why
Histogram
• It is graphic summary of variation in set of data
• Enables us to see patterns that are difficult to see in simple table of numbers
Histogram – Normal Distribution
Histogram – Normal Distribution
A skewed distribution, with one tail longer than the other.
A truncated curve, with the peak at or near the
edge while trailing gently off to the other side, often means that part of the distribution has been removed through screening, 100% inspection, or review. These efforts are usually costly and make good candidates for improvement
efforts.
Histogram – double peaked
A double-peaked curve often means that the data actually reflects two distinct processes with different centers. You will need to distinguish between the two processes to get a clear view of what is really happening in either individual process.
Histogram – Skewed Distribution
A skewed distribution, with one tail longer than the other.
A truncated curve, with the peak at or near the edge while trailing gently off to the other side, often means that part of the distribution has been removed through screening, 100% inspection, or review. These efforts are usually costly and make good candidates for improvement efforts.
Amplifier gain data
8.1 10 8.8 9.7 7.8 9.9 12 8.01 9.3 9
8.2 8.9 10.1 9.4 9.2 7.9 9.5 10.9 7.8 8.3
9.1 8.4 9.6 11.1 7.9 8.5 8.7 7.8 10.5 8.5
11.5 8 7.9 8.3 8.7 10 9.4 9 9.2 10.7
9.3 9.7 8.7 8.2 8.9 8.6 9.5 9.4 8.8 8.3
8.4 9.1 10.1 7.8 8.1 8.8 8 9.2 8.4 7.8
7.9 8.5 9.2 8.7 10.2 7.9 9.8 8.3 9 9.6
9.9 11 8.6 9.4 8.8 8.2 11 9.7 9.1 8
8.7 9.8 8.5 8.9 9.1 8.1 8.1 9.5 8.7 9.3
8.1 10 9.6 8.3 8 9.8 9 8.9 8.1 9.7
8.5 8.2 9 10.2 9.5 8.3 8.9 9.1 10.3 8.4
8.6 9.2 8.5 9.6 9 11 8.6 10 8.8 8.6
Range = High -low
Range =11.7-7.8=3.9db
Result of Amplifier Gain testing
05
1015202530
7.75
- 8.
25
8.25
- 8.
75
8.75
- 9.
25
9.25
- 9.
75
9.75
- 10
.25
10.2
5 - 10.
75
10.7
5 -11.2
5
11.2
5 - 11.
75
11.7
5 - 12.
25
Gain in dB
Nu
mb
er