strategic quality tools _ techniques

8/22/2019 Strategic Quality Tools _ Techniques

1/120

Suzlon Energy Ltd.

STRATEGICSTRATEGIC QUALITYQUALITY

TOOLSTOOLS

&&TECHNIQUESTECHNIQUES

1


2/120

Suzlon Energy Ltd.

Strategic QualityTools & Techniques

2

SUZLON QUALITY ACADEMY

E-COURSE DETAILS

COURSE : STRATEGIC QUALITY TOOLS & TECHNIQUES

VERTICAL : COMMON

TITLE : STRATEGIC QUALITY TOOLS & TECHNIQUES

SUB CODE : A1MODULE TYPE : A/V : PPT : PDF

AUTHOR : GLD

NO. OF SLIDES : 119

LANGAUGE : ENGLISH

REV. NO. : SQA/F/C/A1/001

REV DATE : 01-SEP-11

CONTENT DEV : MR. AMIT DHOLE

Content is for reference purpose only. Specification / content may very due to continuous improvement (For internal circulations only)


3/120

Suzlon Energy Ltd.Objectives

To describe and discuss the roles of various tools and techniques used for

quality planning and continuous improvements.

To acquaint employees with the tools and techniques that are essential

means for designing, manufacturing and delivery of product and services

for customer satisfaction and thereby achieve performance excellence.

3


4/120

Suzlon Energy Ltd.Topics Covered

Quality planning

1) Quality Function deployment (QFD)

2) Process Failure Mode Effects Analysis (PFMEA)

3) Reliability MTBF, MTTF, Failure rate, MTTR, Bathtub curve, Reliability

tests

Continuous Improvement

1) Deming P-D-C-A Cycle

2) Mistake Proofing

3) Kaizen

4


5/120

Suzlon Energy Ltd.

5


6/120

Suzlon Energy Ltd.Quality Function Deployment

Quality Function Deployment (QFD) is a methodology for building the

"Voice of the Customer" into product and service design. It is a systematic

method for transferring customer wants/needs/expectations into product

and process characteristics.

Developed in 1966 by Shigeru Mizuno and Yoji Akao in Japan.

Also Known as House of Quality.

Tool for Concurrent design of products.

Customer attributes (Voice of Customer).

Engineering characteristics (Voice of Engineer).

Competitors Comparison.

6


7/120

Suzlon Energy Ltd.QFD structure based on House of Quality

7


8/120

Suzlon Energy Ltd.Quality Function Deployment Definitions

Capability: The ability to achieve an effect to a standard under specified

conditions through multiple combinations of means and ways to perform a set

of tasks.

Effect: An outcome (condition, behaviour or degree of freedom) resulting from

tasks and actions.

Attribute: A testable or measurable characteristic that describes an aspect of

a system or capability.

Task: An action or activity based upon doctrine, standard procedures, mission

analysis or concepts that may be assigned to an individual or organization.

Condition: A variable of the environment that affects performance of a task.

Standard: The minimum proficiency required in the performance of a task. For

mission-essential tasks of joint forces, each task standard is defined by the

joint force commander and consists of a measure & criterion.

8


9/120

Suzlon Energy Ltd.QFD is a part of Six Sigma Process

9

We need to see how our proposed

design solutions address customer

expectations.

The objectives The beginning of design


10/120

Suzlon Energy Ltd.QFD Design Steps

Identify the customer(s), users, stakeholders etc.

List customer/client requirements (needs & wants).

Prioritize customer requirements use pair wise comparisons.

Benchmark the Competition.

Translate customer requirements/needs into measurable engineering

requirements (called design specifications).

Set engineering targets like time=12 hours or cost less than $250M.

10


11/120

Suzlon Energy Ltd.QFD Structure

11


12/120

Suzlon Energy Ltd.QFD Phases

Phase 1- Product Planning:

Led by the marketing department, Phase 1, or product planning, is also

called The House of Quality. Many organizations only get through this

phase of a QFD process. Phase 1 documents customer requirements,

warranty data, competitive opportunities, product measurements,

competing product measures, and the technical ability of the organizationto meet each customer requirement. Getting good data from the

customer in Phase 1 is critical to the success of the entire QFD process.

Phase 2- Product Design:

Led by the engineering department. Product design requires creativity and

innovative team ideas. Product concepts are created during this phase andpart specifications are documented. Parts that are determined to be most

important to meeting customer needs are then deployed into process

planning, or Phase 3.

12


13/120

Suzlon Energy Ltd.QFD Phases

Phase 3- Process Planning:

Process planning comes next and is led by manufacturing engineering.

During process planning, manufacturing processes are flowcharted and

process parameters (or target values) are documented.

Phase 4- Production Planning:

And finally, in the production planning, performance indicators are

created to monitor the production process, maintenance schedules, and

skills training for operators. Also, in this phase decisions are made as to

which process poses the most risk and controls are put in place to prevent

failures. The quality assurance department in concert with manufacturingleads Phase 4.

13


14/120

Suzlon Energy Ltd.QFD Example: Aeroplane

14

Tech response, engineering characteristics:

Short take-off capability, easy ingress or egress, cabin comfort

Client wishes

1. Operate out of small

airports

2. Contain fewer than 19

passengers

3. Operate in commuter

markets4. Loading and unloading of

passengers in small

airports


15/120

Suzlon Energy Ltd.Requirements Overview

Objectives and design functions are important to know, but

Objectives are statements of what the design must achieve or do, not how

well it must do it.

We need performance specifications to set limits.

Performance specifications provide boundaries to the solution space

Specifications define product performance, not the product itself.

Specifications can limit our design space or direct team efforts

1) If specs are too broad then there is not guidance about where to go.

2) If specs are too narrow or small we may eliminate good design solutions.

15


16/120

Suzlon Energy Ltd.Start the Process

Look at your objectives tree at the top level systems objectives.

List the high level objectives and:

1) Rank order the objectives using pair-wise comparison or another

method of your choice.

2) Rankings will be used for House of Quality weighting factors.

Think about the engineering problem and HOW we will satisfy our

objectives by creating a design.

1) The HOWs are technical objectives or Engineering characteristics

called ECs.2) ECs should affect the customers perceptions of your product.

16


17/120

Suzlon Energy Ltd.Customer needs translation into technical

requirements

17

Systems LevelTechnical

(engineering/system

level) requirements

(EC columns)

Relationships

between NUD

customer needs and

Systems Level Tech

requirements(A matrix)

Either

1) Ranked New,

Unique &

Difficult (NUD)

Customer Needs

or2) customer

attributes

(Rows)

EC/Tech requirements are

product specific

How do we translate a

need into a measurabletechnical requirement?

Example time-responsive

means provide within 24

hours

At the systems level HOW

doesnt mean use ahydrazine rocket


18/120

Suzlon Energy Ltd.Requirement Comments

HOW is not expressed in terms of a design concept provide a sun-

shield is not a good choice for an EC

Functional analysis is important: ECs must convey the right functional

and feature performance information package within (or be deployed

from) restricted launcher volume leads to prescription of volumetric

size goals.

Dont have a requirement that excludes unnecessarily a design concept

in the future

1) Systems level requirements should not state solutions

2) A correct requirement should be able to be fulfilled by severaldifferent design features or components.

Tech requirements take time not just a few minutes of effort

18


19/120

Suzlon Energy Ltd.Requirements Example

Poor Requirement:

Car acoustic damping materials must be able to maintain internal acoustic

noise level at or below 75db.

This is too prescriptive it is not a system level requirement, it is

actually a component requirement.Better Requirement:

Maintain internal car acoustic noise level below 75dB under any set of

driving environment conditions.

This is descriptive and suggests a measurement and a measurable

objective independent of the design concept it allows more than

acoustic damping materials as a solution.

19


20/120

Suzlon Energy Ltd.VOC/NUD Relation Establishment

20

EC/Technical (engineering/system level)

requirements (EC columns)

Relationships between NUD customer needs

and Systems Level Tech requirements

(A matrix)

Ranked New,

Unique &

Difficult

(NUD)

Customer

Needs

(Rows)

X X

X X

X X X

X

X X

X

X X

Which technical requirements affect the VOC/NUDs?

Put an X in the cell


21/120

Suzlon Energy Ltd.Quantifying the Relation

21

Technical (engineering/system level)


39

3

31

1

139

11

31Ranked

New,

Unique &Difficult

(NUD)

Customer

Needs

(Rows)

How strong is

the relationship

between each

requirement and

each VOC/NUD?

Put a 0, 1, 3, 9 in

the cell

9=strong relationship between VOC need and requirement highly dependent

if you satisfy or include this requirement youll make the customer very happy

3=moderate relationship between customer need and design requirement

1=weak relationship between need and requirement

0=no relationship at all


22/120

Suzlon Energy Ltd.How important is each technical requirement

22

Technical (engineering/system level)


39

3

31

1

139

11

31Ranked

New,

Unique &

Difficult

(NUD)

Customer

Needs

(Rows)

2 13 12 3 5 4

We can simply sum or do a weighted sum more later


23/120

Suzlon Energy Ltd.Requirements likely to drive system design

All tech requirements must be fulfilled but a few will stand out.

Requirements that are difficult to fulfill and are critical to customer

satisfaction must be given high priority and team attention.

Some requirements are contradictory

Low cost vs. responsive.

This require a trade.

Find where conflicts exist.

Find where synergies exist.

Make sure that you havent accidentally created a conflict.

23


24/120

Suzlon Energy Ltd.Identifying conflicts & Support

24

Ranked

New,

Unique &

Difficult

(NUD)VOC

Systems Level Technical EC requirements

Relationships between NUD customer

needs and Systems Level Tech

requirements

Technical

correlation matrix

(the roof)

The technical correlation matrix (roof) is a set of matrix elements arranged

in a triangular fashion


25/120

Suzlon Energy Ltd.Relation between technical elements

25

+

_

0

Tech 1 Tech 2 Tech 3

The roof identifies synergies and conflicts and also, how strong is the relation

Use + or 1,3,9 system


26/120

Suzlon Energy Ltd.Do you have Competitors

26

Ranked

New,

Unique &

Difficult

(NUD)

VOC

Systems Level Technical EC

requirements

Relationships between NUDcustomer needs and Systems

Level Tech requirements

Technical

correlation

matrix (roof)

Planning

with

customer

ranking

Quantify and document the capability of competitors to currently fulfill each

system level VOC/NUD requirement.


27/120

Suzlon Energy Ltd.Planned & Customer Ranking Benchmarking

27

Find similar designs or designs that

compete with yours

Look at VOC features

Place yourself in the position of

the customer

Rank how these current designs

fulfill requirements

1=highest ful fi llment

5=lowest fulf illment

Planning matrix

ranking

Design1

Design2

Design3

Design1

5

1

3

3

2

1

1


28/120

Suzlon Energy Ltd.

28


29/120

Suzlon Energy Ltd.Failure Mode Effects Analysis (FMEA)

What is FMEA?

Every product or process has modes of failure. The effects represents the impact of failures. An

FMEA is a tool to:

Identify the relative risks designed into a product or process.

Initiate action to reduce those risks with the highest potential impact.

Track the results of the action plan in terms of risk reduction.

What is FMECA?

FMECA is the result of two steps:

Failure Mode Effects Analysis (FMEA)

Criticality Analysis (CA)

FMECA is just FMEA with Criticality Analysis. There are many different flavours of FMEA. There

are conceptual or Functional FMEAs, Design FMEAs and Process FMEAs. Sometimes during a

design FMEA the analysis will look at a combination of functions and hardware. Sometimes it

will include just hardware, and sometimes the analyst will take a detailed look at the system

down to a piece-part level, especially when critical functions or hardware are involved.

29


30/120

Suzlon Energy Ltd.FMEA Background & History

ThisThis typetype of thinking has been around forof thinking has been around for

hundreds of years. It was first formalized in thehundreds of years. It was first formalized in the

aerospace industry during the Apollo programaerospace industry during the Apollo program

in the 1960s.in the 1960s.

30

Initial automotive adoption in the 1970s.Initial automotive adoption in the 1970s.

Potential serious & frequent safety issues.Potential serious & frequent safety issues.

Required by QSRequired by QS--9000 & Advanced Product Quality Planning Process9000 & Advanced Product Quality Planning Process

in 1994.in 1994.

For all automotive suppliers.For all automotive suppliers.

Now adopted by many other industries.Now adopted by many other industries.

Potential serious & frequent safety issues or loyaltyPotential serious & frequent safety issues or loyalty

issues.issues.


31/120

Suzlon Energy Ltd.FMEA Background & History

An offshoot of Military Procedure MIL-P-1629, titled Procedures for

Performing a Failure Mode, Effects and Criticality Analysis, dated

November 9, 1949.

Used as a reliability evaluation technique to determine the effect of

system and equipment failures. Failures were classified according totheir impact on mission success and personnel/equipment safety.

Formally developed and applied by NASA in the 1960s to improve

and verify reliability of space program hardware.

The procedures called out in MIL-STD-1629A are the most widely

accepted methods throughout the military and commercial industry.

SAE J1739 is a prevalent FMEA standard in the automotive industry.

31


32/120

Suzlon Energy Ltd.FMEA / FMECA Overview

In general, Failure Modes, Effects and Criticality Analysis (FMEA / FMECA)

requires the identification of the following basic information:

Item(s)

Function(s)

Failure(s)

Effect(s) of Failure

Cause(s) of Failure

Current Control(s)

Recommended Action(s)

Plus other relevant details

32


33/120

Suzlon Energy Ltd.Why FMEA is Important?

There are a number of reasons why this analysis technique is so valuable.

Here are just a few:

FMEA provides a basis for identifying root failure causes and developing

effective corrective actions.

The FMEA identifies reliability/safety critical components.

It facilitates investigation of design alternatives at all stages of the design.

Provides a foundation for other maintainability, safety, testability, and

logistics analysis

33


34/120

Suzlon Energy Ltd.What FMEA can do for you?

Identifies Design or process relatedIdentifies Design or process related Failure ModesFailure Modes before they happen.before they happen.

Determines theDetermines the Effect & SeverityEffect & Severityof these failure modes.of these failure modes.

Identifies theIdentifies the CausesCauses and probability ofand probability ofOccurrenceOccurrence of the Failure Modes.of the Failure Modes.

Identifies theIdentifies the ControlsControls and theirand their EffectivenessEffectiveness..

Quantifies and prioritizes theQuantifies and prioritizes the RisksRisks associated with the Failure Modes.associated with the Failure Modes.

Develops & documents Action Plans that will occur to reduce risk.Develops & documents Action Plans that will occur to reduce risk.

34


35/120

Suzlon Energy Ltd.FMEA Terminology

Failure Modes: (Specific loss of a function) is a concise description of how

a part, system or manufacturing process may potentially fail to perform

its functions.

Failure Mode Effect: A description of the consequence or ramification of

a system or part failure. A typical failure mode may have several effectsdepending on which customer you consider.

Failure Mode Causes: A description of the design or process deficiency

(global cause or root level cause) that results in the failure mode.

Failure Mode Controls: The mechanisms, methods, tests, procedures or

controls that we have in place to PREVENTthe cause of the failure modeor DETECTthe failure Mode or Cause should it occur.

35


36/120

Suzlon Energy Ltd.Types of FMEA / FMECA

There are several different types of FMEA. Some of the more common

types of FMEA / FMECA are described below:

36


37/120


CONCEPT FMEA (CFMEA)

The Concept FMEA is used to analyze concepts in the early stages before hardware is

defined (most often at system & subsystem).

It focuses on potential failure modes associated with the proposed functions

of a concept proposal.

This type of FMEA includes the interaction of multiple systems and interaction

between the elements of a system at the concept stages.

Design FMEA (DFMEA)

The Design FMEA is used to analyze products before they are released to production.

It focuses on potential failure modes of products caused by design deficiencies.

Design FMEAs are normally done at three levels system, subsystem & component.

This type of FMEA is used to analyze hardware, functions or a combination.

37


38/120


Process FMEA (PFMEA)

A Process is a sequence of tasks that is organized to produce a product orA Process is a sequence of tasks that is organized to produce a product or

provide a service. A Process FMEA can involve fabrication, assembly,provide a service. A Process FMEA can involve fabrication, assembly,

transactions or services.transactions or services.

The Process FMEA is normally used to analyze manufacturing and

assembly processes at the system, subsystem or component levels.

This type of FMEA focuses on potential failure modes of the process that

are caused by manufacturing or assembly process deficiencies.

38


39/120

Suzlon Energy Ltd.Risk Evaluation Methods

A typical failure modes and effects analysis incorporates some method to

evaluate the risk associated with the potential problems identified

through the analysis. The two most common methods used for Risk

Evaluation are as follows:

Risk Priority Number (RPN)

Criticality Analysis

39


40/120

Suzlon Energy Ltd.Risk Priority Number (RPN)

The RPN calculation is based on Severity, Occurrence & Detection.

Severity: It is related to seriousness of effect. Severity is the numerical

rating of impact on customers.

Occurrence:Occurrence: Is an estimate number of frequencies or cumulative numberIs an estimate number of frequencies or cumulative number

of failures (based on experience) that will occur (in our design concept) forof failures (based on experience) that will occur (in our design concept) for

a given cause over the intended life of the design.a given cause over the intended life of the design.

Detection:Detection: A numerical rating of the probability that a given set of controlsA numerical rating of the probability that a given set of controls

will discoverwill discovera specific Cause of Failure Mode to prevent bad parts leavinga specific Cause of Failure Mode to prevent bad parts leaving

the facility or getting to the ultimate customer.the facility or getting to the ultimate customer.

40


41/120

Suzlon Energy Ltd.Criteria for Severity

41

Effect Rank Criteria

None 1 No effect

Very Slight 2 Negligible effect on Performance. Some users may notice.

Slight 3 Slight effect on performance. Non vital faults will be noticed

by many users

Minor 4 Minor effect on performance. User is slightly dissatisfied.Moderate 5 Reduced performance with gradual performance degradation.

User dissatisfied.

Severe 6 Degraded performance, but safe and usable. User dissatisfied.

High Severity 7 Very poor performance. Very dissatisfied user.

Very High Severity 8 Inoperable but safe.

Extreme Severity 9 Probable failure with hazardous effects. Compliance with

regulation is unlikely.

Maximum Severity 10 Unpredictable failure with hazardous effects almost certain.

Non-compliant with regulations.


42/120

Suzlon Energy Ltd.Criteria for Occurrence

42

Occurrence Rank Criteria

Extremely Unlikely 1 Less than 0.01 per thousand

Remote Likelihood 2 0.1 per thousand rate of occurrence

Very Low Likelihood 3 0.5 per thousand rate of occurrence

Low Likelihood 4 1 per thousand rate of occurrence

Moderately Low

Likelihood

5 2 per thousand rate of occurrence

Medium Likelihood 6 5 per thousand rate of occurrence

Moderately High

Likelihood

7 10 per thousand rate of occurrence

Very High Severity 8 20 per thousand rate of occurrence

Extreme Severity 9 50 per thousand rate of occurrence

Maximum Severity 10 100 per thousand rate of occurrence


43/120

Suzlon Energy Ltd.

Detection Rank CriteriaExtremely Likely 1 Can be corrected prior to prototype/ Controls will almost certainly

detect

Very High Likelihood 2 Can be corrected prior to design release/Very High probability of

detection

High Likelihood 3 Likely to be corrected/High probability of detection

Moderately High

Likelihood

4 Design controls are moderately effective

Medium Likelihood 5 Design controls have an even chance of working

Moderately Low

Likelihood

6 Design controls may miss the problem

Low Likelihood 7 Design controls are likely to miss the problemVery Low Likelihood 8 Design controls have a poor chance of detection

Remote Likelihood 9 Unproven, unreliable design/poor chance for detection

Extremely Unlikely 10 No design technique available/Controls will not detect

Criteria for Detection

43


44/120

Suzlon Energy Ltd.Calculation of Risk Priority Number (RPN)

To use the Risk Priority Number (RPN) method to assess risk, the analysis

team must:

Rate the severity of each effect of failure.

Rate the likelihood ofoccurrence for each cause of failure. Rate the likelihood of prior detection for each cause of failure (i.e. the

likelihood of detecting the problem before it reaches the end user or

customer).

Calculate the RPN by obtaining the product of the three ratings:

RPN = Severity x Occurrence x Detection

44


45/120

Suzlon Energy Ltd.Criticality Analysis

Criticality-MIL-STD-1629 Approach:

Criticality is a measure of the frequency of occurrence of an effect.

May be based on qualitative judgement or

May be based on failure rate data (most common)

The MIL-STD-1629A document describes two types of criticality analysis:

1. Qualitative analysis:

Used when specific part or item failure rates are not available.

2. Quantitative analysis:

Used when sufficient failure rate data is available to calculate

criticality numbers.

45


46/120

Suzlon Energy Ltd.Qualitative Approach

Because failure rate data is not available, failure mode ratios and failuremode probability are not used.

The probability of occurrence of each failure is grouped into discrete levels

that establish the qualitative failure probability level for each entry based

on the judgment of the analyst.

The failure mode probability levels of occurrence are:

Level A - Frequent

Level B - Reasonably Probable

Level C - Occasional

Level D - Remote

Level E - Extremely Unlikely

46


47/120

Suzlon Energy Ltd.Quantitative Approach

Failure Mode Criticality (CM) is the portion of the criticality number for anitem, due to one of its failure modes, which results in a particular

severity classification (e.g. results in an end effect with severity I, II,

etc...).

MIL-STD-1629 Severity Levels

1) Category I - Catastrophic: A failure which may cause death or weapon

system loss (i.e., aircraft, tank, missile, ship, etc...)

2) Category II - Critical: A failure which may cause severe injury, major

property damage, or major system damage which will result in mission loss.

3) Category III - Marginal: A failure which may cause minor injury, minor

property damage, or minor system damage which will result in delay or loss of

availability or mission degradation.

4) Category IV - Minor: A failure not serious enough to cause injury, property

damage or system damage, but which will result in unscheduled maintenance

or repair.

47


48/120

Suzlon Energy Ltd.Quantitative Approach

The quantitative approach uses the following formula for Failure ModeCriticality:

Cm = pt

Where,

Cm = Failure Mode Criticality

= Conditional probability of occurrence of next higher failure effect

= Failure mode ratio

p = Part failure rate

T = Duration of applicable mission phase

48


49/120

Suzlon Energy Ltd.Criticality Analysis Example

49

A resistor R6 with a failure rate of .01 failures per million hours is located on the Missile Interface Board of

the XYZ Missile Launch System. If the resistor fails, it fails open 70 % of the time and short 30 % of the time. Ifit fails open, the system will be unable to launch a missile 30 % of the time, the missile explodes in the tube

20 % of the time, and there is no effect 50 % of the time. If it fails short, the performance of the missile is

degraded 50 % of the time and the missile inadvertently launches 50 % of the time. Mission time is 1 hour.

p = 0.01 in every case

= 0.7 for open

= 0.3 for unable to fire

= 0.2 for missile explodes

= 0.5 for no effect

= 0.3 for short

= 0.5 for missile performance degradation

= 0.5 for inadvertent launch

Cm for R6 open resulting in being unable to fire is (.3)(.7)(.01)(1)=0.0021

Cm for R6 open resulting in a missile explosion is (.2)(.7)(.01)(1)=0.0014

Cm for R6 open resulting in no effect is (.5)(.7)(.01)(1)=0.0035

Cm for R6 short resulting in performance degradation is (.5)(.3)(.01)(1)=0.0015

Cm

for R6 short resulting in inadvertent launch is (.5)(.3)(.01)(1)=0.0015


50/120

Suzlon Energy Ltd.Procedure to conduct PFMEA

1. Select the Process:

The first thing the user has to do is to select the process to analyse. The

importance of the process in terms of the impact of potential failures is a

parameter that has to be taken into account as selection criteria.

2. Review the Process:

Gather a team (be sure to include people with various job responsibilities

and levels of experience) and give each member a copy of the process

blueprint or description. The process could be analysed and described in a

flowchart. Also, have the team use the process so all members can

become familiar with the way it works.

3. Brainstorm Potential Failure Modes:

Look at each stage of the process and identify ways it could potentially fail,

things that might go wrong.

50


51/120


4. List Potential effects of each Failure Mode:

List the potential effect of each failure next to the failure. If a failure has

more than one effect, write each in a separate row. To identify the effects

and the causes(G) of the effects someone can use Cause and Effects

analysis (fishbone diagram).

5. Assign Severity Rating for each effect:

Give each effect its own severity rating (from 1 to 10, with 10 being the

most severe). If the team can't agree on a rating, hold a vote. To quantify

or prioritize the effects someone can use Pareto analysis.

6. Assign an occurrence rating for each failure mode:Collect data on the failures of your product's competition. Using this

information, determine how likely it is for a failure to occur and assign an

appropriate rating (from 1 to 10, with 10 being the most likely).

51


52/120


7. Assign a detection rating for each failure mode & effect:

List all controls currently in place to prevent each effect of a failure from

occurring and assign a detection rating for each item (from 1 to 10, with

10 being a low likelihood of detection).

8. Calculate the Risk Priority Number (RPN) for each effect:

Multiply the severity rating by the occurrence rating by the detection

rating.

9. Prioritize the failure modes for action:

Decide which items need to be worked on right away. For example, if you

end up with RPNs ranging from 50 to 500, you might want to work first onthose with an RPN of 200 or higher.

52


53/120


10. Take action to eliminate or reduce the high risk failure modes:

Determine what action to take with each high risk failure and assign a

person to implement the action.

11. Calculate the resulting RPN as the failure modes are reduced or

eliminated:

Reassemble the team after completing the initial corrective actions and

calculate a new RPN for each failure. Then you may decide you've taken

enough action or you want to work on another set of failures.

12. Use and update FMEA form:

After a process has been analysed in terms of identify, quantify and takeinitial measures for the potential failures, a person has to be assigned to

monitor the effectiveness of the actions taken (see step 9) and the results

in case of a failure. Also new problems raised have to be analysed and

inserted in the FMEA form.

53


54/120

Suzlon Energy Ltd.Process FMEA Example

54

Automotive Industry Action Group (AIAG) FMEA-3 Format is used.


55/120

Suzlon Energy Ltd.Process FMEA Work Sheet

55


56/120

Suzlon Energy Ltd.Failure Causes

56


57/120

Suzlon Energy Ltd.Recommended Actions (Summary Report)

57


58/120

Suzlon Energy Ltd.Current Controls

58


59/120

Suzlon Energy Ltd.Advantages of PFMEA

Elimination of process problems in conceptual phase.

Helps to identify places of higher risks associated with processes involved.

Helps to develop technical specifications for processes and workstations.

Provides inputs in developing Process Control Plan.

Creates a platform for exchanging information (increase of

process/product awareness inside core team).

Acts as a database management tool for process initialization and changes

etc.

59


60/120

Suzlon Energy Ltd.Disadvantages of PFMEA

Time Consuming process.

High Initial investment involved.

Supervision, updating and maintenance of documentation.

Not including customers: Customers have better view on potential failure

modes than internal personnel.

Has a tendency to become a full time job for an individual which is not

recommended.

60


61/120

Suzlon Energy Ltd.

61


62/120

Suzlon Energy Ltd.Reliability

Reliability is The probability that an item will perform a required function,under stated conditions, for a stated period of time.

Put more simply, it is The probability that an item will work for a stated

period of time.

There are number of ways of expressing reliability, following are the most

commonly used in different types of industries:

1. Mean Time Between / To Failure (MTBF / MTTF).

2. Failure Rate.

3. Mean Time To Repair.

62


63/120

Suzlon Energy Ltd.Mean Time Between/To Failure (MTBF/MTTF)

Reliability is quantified as MTBF (Mean Time Between Failures) forrepairable product and MTTF (Mean Time To Failure) for non-repairable

product.

MTBF is the mean operating time (up time) between failures of a specified

item of equipment or a system. MTBF is commonly used to express the

overall reliability of items of equipment and systems.

MTTF is stands for Mean Time To Failure. To distinguish between the two,

the concept of suspensions must first be understood. In reliability

calculations, a suspension occurs when a destructive test or observation

has been completed without observing a failure.

Computation for both MTTB/MTTF are same.

63


64/120

Suzlon Energy Ltd.Calculation of MTBF

The formula for calculating the MTBF is

Where,

= Mean time between/to failure

T= Total running time/cycles/miles/etc. during an investigation

period for both failed and non-failed items.

r= The total number of failures occurring during the investigationperiod.

64

MTBF = Total Operating Time / No. of Failures

= T / r


65/120

Suzlon Energy Ltd.Failure Rate

Failure Rate is the ratio of Number of failures to Total operating time.

Where, = Failure rate (sometimes referred to as the hazard rate)

T= Total running time/cycles/miles/etc. during an investigation

period for both failed and non-failed items.

r= The total number of failures occurring during the investigation

period.

Failure rate is measured in units of time-1, such as failures per million

hours. Failure rate is often used to express the reliability of simple items

and components. It is also frequently used to express the reliability of

particular functions, for example the dangerous failure rate of a safety

system.

65

Failure Rate = No. of Failures / Total operating Time

= r / T


66/120

Suzlon Energy Ltd.Relationship between MTBF & Failure Rate

Since,

MTTF = Total Operating Time / No. of Failures

And

Failure Rate () = No. of Failures / Total operating Time

Thus, it is implied that

This is true, but only if the failure rate does not change over time. Usually

this is so for simple equipment but not so for redundant systems.

66

MTBF = 1/


67/120

Suzlon Energy Ltd.Relationship between MTBF & Failure Rate

As MTBF and are measuring the same thing, why have different terms?

MTBF (years, hours) is most often used to express the overall reliability

of equipment.

MTTF (Mean time to failure, years, hours) more correct for items thatare not repaired

(hr-1, pmh, FITs) is convenient to use for components, and it is easy to

calculate the MTBF of an item of equipment from the sum of the

component s. It is also commonly used to express the reliability of a

particular function, such as a safety function.

67


68/120

Suzlon Energy Ltd.Mean Time To Repair (MTTR)

Mean Time To Repair (MTTR) is the average time to repair the item of

equipment or system or the entire system.

Where,

= Repair Rate = Number of Repairs / Time period for all Repairs

The MTTF and MTTR both measure the time that the system is running

between repairs, and the time the system is down for repairs. But, they

must be combined for the more useful measure MTBF (Mean Time BeforeFailure),

MTBF = MTTF + MTTR

The difference between MTBF and MTTR is often small, but when critical

the difference must be observed.

68

MTTR = 1 /


69/120

Suzlon Energy Ltd.Availability

Availability can be defined as The proportion of time for which theequipment is able to perform its function.

Availability is different from reliability in that it takes repair time into

account. An item of equipment may not be very reliable, but if it can be

repaired quickly when it fails, its availability could be high.

From the above diagram, we can see what is meant by Up Time the time

when the equipment is available - and Down Time the time when the

equipment has failed and so is unavailable.

The averages of each of these are

1. Mean Up Time, which we have already seen is known as the MTBF.

2. Mean Down Time, or MDT.

69


70/120


By Definition,

70


71/120


Sometimes Mean Time To Repair (MTTR) is used in this formula instead ofMDT. But MTTR may not be the same as MDT because:

The failure may not be noticed for some time after it has occurred.

It may be decided not to repair the equipment immediately.

The equipment may not be put back in service immediately it is repaired.

Whether MDT or MTTR is used, it is important that it reflects the total

time for which the equipment is unavailable for service, otherwise the

calculated availability will be incorrect.

In the process industries, MTTR is often taken to be 8 hours, the length of

an ordinary work shift but in reality the repair time in a particularinstallation might be different.

71


72/120

Suzlon Energy Ltd.Unavailability

Sometimes, Unavailability can be the useful term. It is defined as

72


73/120

Suzlon Energy Ltd.Bath Tub Curve

The life of a population of units can be divided into three distinct periods.Figure 1 shows the reliability bathtub curve which models the cradle to

grave instantaneous failure rates vs. time.

If we follow the slope from the start to where it begins to flatten out this

can be considered the first period.

73


74/120


The first period is characterized by a decreasing failure rate. It is whatoccurs during the early life of a population of units. The weaker units die

off leaving a population that is more rigorous. This first period is also

called infant mortality period.

The next period is the flat portion of the graph. It is called the normal life.

Failures occur more in a random sequence during this time. It is difficult topredict which failure mode will manifest, but the rate of failures is

predictable. Notice the constant slope in above figure.

The third period begins at the point where the slope begins to increase

and extends to the end of the graph. This is what happens when units

become old and begin to fail at an increasing rate.

74


75/120


Early Life Period:

There is always the risk that, although the most up to date techniques are

used in design and manufacture, early failures will occur. In order to offset

these risks - especially in newer product - organization may consume some

of the early useful life of a module via stress screening.

Some of the design techniques include: burn-in (to stress devices underconstant operating conditions); power cycling (to stress devices under the

surges of turn-on and turn-off); temperature cycling (to mechanically and

electrically stress devices over the temperature extremes); vibration;

testing at the thermal destruct limits; highly accelerated stress and life

testing etc.

This technique allows the units to begin their operating life somewhere

closer to the flat portion of the bathtub curve instead of at the initial peak,

which represents the highest risk of failure.

75


76/120


Useful Life Period:

As the product matures, the weaker units die off, the failure rate becomes

nearly constant, and modules have entered what is considered the normal

life period.

This period is characterized by a relatively constant failure rate.

The length of this period is referred to as the system life of a product or

component.

It is during this period of time that the lowest failure rate occurs.

The useful life period is the most common time frame for making reliability

predictions.

76


77/120


Wear Out Period:

As components begin to fatigue or wear out, failures occur at increasing

rates.

Wear out may be caused by breakdown in power supplies, breakdown of

electrical components that are subject to physical wear and electrical and

thermal stress, friction in mechanical components, running machineswithout proper lubrication etc.

It is this area of the graph that the MTBFs or FIT rates calculated in the

useful life period no longer apply.

A product with a MTBF of 10 years can still exhibit wear out in two years.

77


78/120

Suzlon Energy Ltd.Reliability Tests

Reliability Test is the general term for reliability determination tests andreliability compliance tests. In other words, reliability characteristics

values (failure rate, reliability, average life, MTTF, etc.), which are scales

representing the time-dependent quality of products, are estimated and

verified statistically from the test data.

These tests also play an important role in improving reliability by analyzingfailures which occur during tests and clarifying these failure mechanisms.

Reliability tests provide the greatest effects when statistics and failure

physics function reciprocally.

Reliability Tests are specific to the products, equipments, parts, items and

functions of the particular product. There may be different tests used fordifferent products depending on their application and functionality.

78


79/120

Suzlon Energy Ltd.Reliability Tests

Specific purpose of Reliability Tests are

Product reliability assurance

Evaluating new designs, components, processes and materials

Investigating test methods

Discovering problems with safety

Accident countermeasures

Determining failure distributions

Collecting reliability data

Reliability control

79


80/120

Suzlon Energy Ltd.Generic Reliability Tests

Raw Material Tests

Destructive Testing

Non Destructive Testing

Running tests:

No Load Testing

Part Load Testing

Full Load Testing.

Accelerated life Testing

Functional Testing

Stress Testing

80


81/120

Suzlon Energy Ltd.

81


82/120

Suzlon Energy Ltd.Deming PDCA

A well-known general model for all areas of strategic and operationalmanagement.

This model became popular especially through American Dr. W. Edwards

Deming's lectures of managerial quality during several decades (from

1950's to 1990's).

However, originally the model was created by American Dr. Walter

Shewhart in the 1920's.

82


83/120

Suzlon Energy Ltd.Objectives of Deming PDCA

To satisfy internal and external customers by providing outputs that

consistently meet their requirements in terms of quality and always on

time.

To provide these outputs efficiently at a cost that is within the budget.

To ensure consistency of daily/routine work creating pleasant and safework environment

To provide autonomy to people working on the process for respect and

dignity

To continuously develop people capability.

83


84/120

Suzlon Energy Ltd.Deming PDCA

PDCA model describes how a consistent management consists of fourconsecutive activities:

P: Planning business activities what should be done and what results

should be achieved.

D: Doing business obligations according to the plans.

C: Checking what was done and what results achieved.

A: Acting rationally taking into account the observations and results of the

checking.

84


85/120

Suzlon Energy Ltd.PDCA Model for Management

85


86/120

Suzlon Energy Ltd.PDCA Model for Management

Above Figure depicts PDCA model for management (or so called Deming /

Shewhart cycle) and its application in strategic and operational business

management

In organizational environments the PDCA model is to be applied in three

different scopes:

Control: Managing daily operations in business processes in order toachieve the specified results. Normally rectifying nonconformities is

carried out in connection with control.

Prevention and operational improvements: Solving acute problems,

preventing nonconformities, and finding / implementing operational

step by step improvements in business processes.

Breakthrough improvements: Innovating and implementing

strategically significant changes in the way doing business.

86


87/120

Suzlon Energy Ltd.PDCA Cycle

Plan

Clearly define the problem (P1).

Collect evidence of problem (P2).

Identification of impacts or opportunities (P3).

Measurement of problem & Validation of data (P4).

Measure(s) of effectiveness for problem solving efforts (P5).

Do

Generate possible causes of problem (D1).

Broke-Need-Fixing causes identified, worked on (D2).

Write Experimental Test or Action Plan (D3/D4).

Identification of resources required (D5).

87


88/120


Do

Revise the PDCA Timetable, depending on plan (D6).

Management Team Review / Approval (D7).

Check

Carry out Experimental Test or Action Plan (C1/C2).

Analyze data from Experimental or Action Plan (C3).

Decisions-Back to Do Stage or Proceed (C4).

Implementation Plan to Make Change Permanent (C5).

Force Field Analysis on Implementation (C6).

Management Team Review/Approval (C7).

88


89/120


Act

Carry out Implementation Plan (A1).

Post-Measure of Effectiveness (A2).

Analyze Results vs. Team Objectives (A3).

Team Feedback Gathered (A4).

Management Team Close-out Meeting (A5).

89


90/120

Suzlon Energy Ltd.

90


91/120

Suzlon Energy Ltd.Mistake Proofing

Mistake proofing is a powerful tool for creating more stable processes byreducing defects.

Mistake proofing is critical to the lean organization for creating and

maintaining process stability.

For the manufacturer, mistake-proofing techniques can be applied to the

manufacturing process or the product design itself to preventmanufacturing errors.

They can also be used outside of manufacturing: hospitals, financial

institutions and other service organization have successfully used mistake-

proofing techniques.

While mistake proofing in some forms has been around for a very long

time, it was Toyota that formalized a system. Toyotas Shigeo Shingo

developed an approach called Zero Quality Control (ZQC).

91


92/120


ZQC, sometimes referred to as zero defects, is based on the principlethat defects are prevented by controlling the performance of a process so

that it cannot produce defects even when a machine or person makes a

mistake.

Poke-yoke, or mistake proofing, is one key aspect of ZQC.

Poka-yoke is a Japanese term that means "mistake-proofing".

A poka-yoke is any mechanism that helps an equipment operator avoid

(yokeru) mistakes (poka). Its purpose is to eliminate product / services /

process defects by preventing, correcting, or drawing attention to human

errors as they occur.

Poke-yoke or mistake proofing systems use sensors or other devices that

make it nearly impossible for an operator to make an error.

92


93/120


Poka-Yoke or Mistake proofing systems regulate the production processand prevent defects in one of two ways:

Control system: stops the equipment when an irregularity happens or

locks a clamp on the workpiece to keep it from moving on when it is not

completely processed. This is the better system since it is not operator

dependent. Warning system : signals the operators to stop the machine or address the

problem. This type of system is operator dependent.

Basic Methods

There are three types of poke-yoke methods: contact methods, fixed-

value or Counting methods and motion-step/motion-sequence methods.

93


94/120

Suzlon Energy Ltd.Contact Method

A contact method functions by detecting whether a sensing device makescontact with a part or object within the process.

An example of a physical contact method is limit switches that are

pressed when cylinders are driven into a piston. The switches are

connected to pistons that hold the part in place. In this example, a

cylinder is missing and the part is not released to the next process.

94


95/120

Suzlon Energy Ltd.Physical Contact Devices

95

Limit Switches

Toggle Switches


96/120

Suzlon Energy Ltd.Energy Contact Devices

Photoelectric switches can be

used with objects that are

translucent or transparent

depending upon the need.

Transmission method: two units,

one to transmit light, the other

to receive.

Reflecting method: PE sensor

responds to light reflected fromobject to detect presence.

96

If object breaks the transmission, the machine is signaled to shut down.


97/120

Suzlon Energy Ltd.Contact Devices

97

An example of a

contactdevice using a

limit switch. In this

case the switch makes

contactwith a metal

barb sensing its

presence. If no

contactis made the

process will shut

down.


98/120

Suzlon Energy Ltd.Fixed Value/Counting Method

Used when afixednumber of operations are required within a process, orwhen a product has a fixed number of parts that are attached to it.

A sensor counts the number of times a part is used or a process is

completed and releases the part only when the right count is reached.

98

In the example to the right a

limit switch is used to detect

and count when the required

amount of holes are drilled.

The buzzer sounds alerting the

operator that the appropriateamount of steps have been

taken in the process.


99/120

Suzlon Energy Ltd.Fixed Value/Counting Method

Another approach is to count the number of parts or components requiredto complete an operation in advance. If operators finds parts leftover

using this method, they will know that something has been omitted from

the process.

99

I have an extra

part. I must have

omitted a step!


100/120

Suzlon Energy Ltd.Motion Sequence/Motion Step Method

The third poka-yoke method uses sensors to determine if a motion or astep in a process has occurred. If the step has not occurred or has

occurred out of sequence, the sensor signals a timer or other device to

stop the machine and signal the operator.

10

This method uses sensors and photo-electricdevices connected to a timer. If movement

does not occur when required, the switch

signals to stop the process or warn the

operator.


101/120

Suzlon Energy Ltd.Motion Sequence/Motion Step Method

In order to help operators select the right parts for the right step in a

process the sequencing aspect of the motion-step method is used. Thisis especially helpful when using multiple parts that are similar in size and

shape.

10

In order to help operators select the right parts for the right step in a process

the sequencing aspect of the motion-step method is used. This is especially

helpful when using multiple parts that are similar in size and shape.

Machine Indicator Board


102/120

Suzlon Energy Ltd.Types of Sensing Devices

Sensing devices that are traditionally used in poka-yoke systems can bedivided into three categories:

1. Physical contact devices

2. Energy sensing devices

3. Warning Sensors

Each category of sensors includes a broad range of devices that can be

used depending on the process.

10


103/120

Suzlon Energy Ltd.Physical Contact Sensors

10

These devices work byphysically touching

something. This can be

a machine part or an

actual piece being

manufactured.

In most cases these

devices send an

electronic signal when

they are touched.

Depending on the

process, this signal canshut down the

operation or give an

operator a warning

signal.


104/120

Suzlon Energy Ltd.Energy Sensors

10

Fiber optic

Photoelectric

Vibration

These devices work by

using energy to detect

whether or not an

defect has occurred.


105/120

Suzlon Energy Ltd.Warning Sensors

10

Color Code

Lights

Lights connected to

Micro switches &

timers

Warning sensors signal

the operator that there is

a problem. These sensors

use colors, alarms, lights

to get the workersattention !

These sensors may be

used in conjunction with

a contact or energy

sensor to get the

operators attention.


106/120

Suzlon Energy Ltd.

10


107/120

Suzlon Energy Ltd.Kaizen

What is Kaizen?

KAI Take apart and make better

ZEN Think. Make good the actions of others. Do good deeds. Helpeach other

KAIZEN Make peoples jobs easier by taking them apart, studying them,

and making improvements

Also known as: The Deliberate Application of Common Sense

10


108/120

Suzlon Energy Ltd.Kaizen History

First made popular by Toyota as part of their production system (TPS or

Lean Manufacturing) in the 1970s.

Discovered and described in books in the West starting in the 1980s.

Popular in American Auto and Aerospace industries in the 1990s (Kaizen

Blitz).

Key tool in Lean Production today.Why to Use Kaizen?

To solve problems (without already knowing the solut ion)

To eliminate waste (Muda)

Transportation, Inventory, Motion, Waiting, Over-production,Over-processing, Defects

Create ownership and empowerment

Support lean thinking

10


109/120

Suzlon Energy Ltd.Seven Types of Waste

10

KODAK OPERATING SYSTEM

CALL ITCALL IT

TWENTY?TWENTY?

22 TO BE ON22 TO BE ON

THE SAFE SIDE!THE SAFE SIDE!

TENTEN

PLEASE!PLEASE!

Over - Production

Taiichi Ohnos 7 Wastes


Motion


Defects / Rejects / Re-workKODAKOPERATINGSYSTEM

How do you spell that?

Over -Processing

KODAKOPERAT ING SYSTEM

Inventory

$$$$

$$$$$$

$$$$

$$

$$

$$$$

$$

KODAKOPERATINGSYSTEM

Transportation


Waiting


110/120

Suzlon Energy Ltd.Kaizen Workshop

A short burst of intense activity & effort

(can range in hours to days)

Emphasis on action over analysis

Focused on improving the Value Stream and achieving flow

Flow for materials and information

Driven to resolving a specific problem or achieving a specific goal. (Dont

bite off more than you can chew)

11


111/120

Suzlon Energy Ltd.Characteristics of Kaizen Workshop

A focus on an area or process to achieve a specific goal.

Includes a team that is empowered to make changes.

Team make-up should include: Operators, Maintenance, Outside Eyes,and a process owner. (If possible a customer).

Supported by management with Money, Time, and frequent gembaactivity.

Managed to resolution and a commitment to sustain.

11


112/120

Suzlon Energy Ltd.Kaizen Preparation

Pre Kaizen steps are performed so that the Kaizen is as effective and wastefree as possible

Define the opportunity

Cost, Quality, Waste, Safety - Specific

Form & train the team

They must be dedicated resources commitment

They must be trained in specifics regarding the task at hand. (i.e.

process knowledge, lean tools)

Set goals / collect baseline data

Is the problem well understood what does success look like?

Leader & team responsibilities

11


113/120

Suzlon Energy Ltd.Kaizen Team Formation

Team composition & training is critical to the success of the team. Composition should reflect the diversity of the work center.

A team generally consists of 6-10 people.

Each member will be chosen to perform a specific role everybody works.

The kaizen team generally meets first for instructions, brainstorming ofideas and development of action plans.

Kaizen teams gather their own facts by observing the issues or problems

for themselves.

Observations show many issues that cannot be detected viewing reports

and data.

Once the kaizen team has obtained improvement, most groups will give a

presentation to management.

11


114/120

Suzlon Energy Ltd.Kaizen Cycle

Kaizens usually follow the Plan-Do-Check-Act (PDCA) methodology. As the PDCA model suggests, once the actions are planned, they are

carried out, checked and actions taken based on the results.

The PDCA cycle is continued until the problem is sufficiently solved.

11


115/120

Suzlon Energy Ltd.Kaizen Area Profile: Summary Sheet

11

Instructions for filling out the Area Profile

Team # :

Event Description: Event Dates:

Describe scope and scale of project

Preliminary Objectives: Team:

Name RoleBe specific and state measurable objectives. Sue Team Leader

Pete Co-LeaderDo not say " significantly reduce costs by eliminating waste" Jane Outside eyes

Do say "reduce cost of operation by $500k".

Production Requirements (Takt Time):

Consultant:

Takt = Available time Calculate in secondsCustomer demand Sensei's Facilitator:

Process Information: Current Situation and Problems

A picture of the process flow - show the Current state in a Be specificpicture, not words

For example:Service desk hold times at 92 seconds10% of all callers hang up before talking to an agent3% Rework due to tolerance failure


116/120

Suzlon Energy Ltd.Kaizen Target Sheet

11


117/120

Suzlon Energy Ltd.Kaizen Report Sheet

11


118/120

Suzlon Energy Ltd.Dos and Don'ts of Kaizen

11

Do be open minded to all

approaches

Do try as many ideas as

possible. A minimum of

three.

Do as many observations of

reality as possible (10).

Do include one person who is

convinced it cant be done.

Do make sure management iscommitted to resolving the

issue and supporting the

team.

Dont utilize to implement your

solution

Dont just sit around and

brainstorm or justify the

current way things are done.

Dont assume you know the

problem

Dont put more than one of

these people on the team.

Dont hold a Kaizen to resolve

an issue that is not driving abusiness goal.


119/120

Suzlon Energy Ltd.

11

Suzlon Energy Ltd.


120/120

Suzlon Energy Ltd.

strategic quality tools _ techniques

Documents