01-Reliability Management (1)

8/12/2019 01-Reliability Management (1)

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Reliability

MANAGEMENT

By

Lt Col (Retd) Navneet Sood

B.Tech, M.Tech, PGDBA, PMP, CRE, CMQ/OE


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Why R&M ? Reduced Design Cycle Time

Optimal Design

Survivability in Manufacturing Survivability in Actual Usage

Cost Reduction

Customer Satisfaction

Competitive in Business


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The aim of this session is to

give you an overview about theReliabilityManagementand its

relevance for a BEL design

engineer.

aIM


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Phase-I : Reliability Terminology

Phase-II : Interrelationship of Safety-Quality-Rel

Phase-III : Benefits of Reliability Engineering

Phase-IV : Rel in Product/Process Development

Phase-V : Liability & Warranty Management

Phase-VI : Customer Needs & Supplier Reliability

Phase-VII: Product Life Cycle & Systems Engg

PReVIEW


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Reliability

Terminology

Phase-I


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What is Reliability ?

Fitness for Use

Probability of Survival

Probability of SatisfactoryOperation of an Equipment for

a Specified period of Time tunder Intended /actualOperating Conditions.


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Reliability: Definition

The duration or probability offailure free performance under

stated conditions.The Probability that an item

will perform a required

function without failure understated conditions for a stated

period of Time.


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Types of SystemsThere are 2 basic types of systems

Non - Repairable Repairable


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TERMINOLOGY1. Failure Rate () :No. of failures per hour, per cycle, per mile, etc.

2. MTBF (1/) :Mean Time Between Failures (Repairable Items) is

equal to the reciprocal of failure rate.

3. MTTF :Mean Time to Failure (Non-Repairable Items)

4. Maintainability : The Probability that an item will be retained in

or restored to a specified condition within

a given period of time, when the maintenance

is performed in accordance with prescribed

procedures and resources.

5. Availability : Normally defined in connection with repairable

systems as the time fraction where the system is

functioning or can be made to function.

Availability= MTBF / (MTBF + MTTR)


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Reliability is described by means of the single parameter

Exponential Distribution: R(t)=e-t

Where:

= Failure rate

t = Mission time

M = MTBF = 1/

Reliability of a System:

Rs = R1*R2 *R3************Rn

Rs = e-st

Rs = e(1 + 2+.+ n)

tAdditive term

NOTE: THESE CONCEPTS WERE ACCEPTED IN EARLY 1950SAND HAVE BEEN APPLIED EVER SINCE.

GENERAL CONCEPTS


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MTBF Exercise

Given R= 0.95, t = 50 hrs, Whatis the MTBF goal ?

What is the goal if R=0.99?

What is the Reliability if themission time is as large as theMTBF ?

974 Hrs

0.368

4974Hrs


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What is the Mission Time?

Comsat

Mazda

Endeavor

Cruise


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Reliability Vs Mission Time

Desirable that MTBF >> Miss ion Time

Mission Time (t) Reliability (R)

t = MTBF 0.368

t = MTBF/2 0.606538

t = MTBF/4 0.77880091

t = MTBF/10 0.904837

t = MTBF/100 0.9900498

t = MTBF/1000 0.999000505


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Reliability Vs Mission Time


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Interrelationship

of Safety, Quality

& Reliability

Phase-II


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Safety: Definition Safety is the state of being safe, the

condition of being protected against physical,social, spiritual, financial, political,emotional, occupational, psychological,

educational or other types or consequencesof failure, damage, error, accidents, harm orany other event which could be considerednon-desirable.

Safety can also be defined to be the controlof recognized hazards to achieve anacceptable level of risk.


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Product SafetySafety Related Data Issues: w.r.t. feedback, Customer

feedback, design data and field data can be collected,Analyzed and used to improve the safety of a product.

During Design Phase: It is important to doc all designreviews, FMECAS, FTAs, trade off Studies, etc. Results should

be compared to contractual requests. In The Production Phase: All the screening and functional

testing should be performed to prescribed. Results of thesetests should be recorded and analyzed.

When Failures Occur In The Field: The detailed informationshould be recorded for each failure occurrence (Date andTime, Operation and Environmental conditions, FMs, Actionsto repairs Active op time, operator and his skill level, cause,failure analysis, Recommended corrective action, CAimplementation/ effective)


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Meaning of Quality

Websters Dictionarydegree of excellence of athing

American Society for Qualitytotality of features andcharacteristics that satisfyneeds

Consumers and Producers

Perspective


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Meaning of Quality:

Consumers Perspective Fitness for use how well product or

service does what itis supposed to

Quality of design designing quality

characteristics into aproduct or service

A Mercedes and aFord are equally fitfor use, but withdifferent designdimensions


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Meaning of Quality:

Producers Perspective Quality of ConformanceMaking sure a product or service is

produced according to design

if new tires do not conform tospecifications, they wobble

if a hotel room is not clean when aguest checks in, the hotel is notfunctioning according tospecifications of its design


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Meaning of Quality:

A Final Perspective Consumers and producers

perspectives depend on each

other Consumers perspective: PRICE

Producers perspective: COST

Consumers view mustdominate


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Fitness forConsumer Use

Producers Perspective Consumers Perspective

Quality of Conformance

Conformance to

specifications Cost

Quality of Design

Quality characteristics Price

MarketingProduction

Meaning of Quality

Meaning of Quality


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Quality: Definition

Quality is the totality of features andcharacteristics of a product or service thatbear on its ability to satisfy stated or impliedneeds.

Some goals of quality programs include:

Fitness for Use. (Is the product or service capableof being used?)

Fitness for Purpose. (Does the product or servicemeet its intended purpose?)

Customer Satisfaction. (Does the product orservice meet the customer's expectations?)

Conformance to the Requirements. (Does theproduct or service conform to the requirements?)


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Management

Quality

Safety

Reliability

Interrelationship


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Definition

Reliabilityis defined as theprobability that an item willperform a required function

without failure under statedconditions for a specifiedperiod of time.

Qualityis a snapshot at thestart of life and reliabilityis amotion picture of the day-by-day operation.


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Safety, Quality& Reliability

Quality and Reliability Engineersprovide different inputs into the designprocess.

Quality Engineerssuggest changes thatpermit the item to be produced withintolerance at a reasonable cost.

Reliability Engineersmakerecommendations that permit the itemto function correctly for a longer period

of time.


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Safety, Quality& ReliabilitySometimes equipment failure can

have a major impact on human safetyand / or health. From the point ofview of assessing product reliability,

we treat these kinds of catastrophicfailuresno differently from the failurethat occurs when a key parameter

measured on a manufacturing tooldrifts slightly out of specification,calling for an unscheduled

maintenance action.


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Safety, Quality& Reliability

It is up to the Reliability Engineer(and the relevant customer) todefine what constitutes a failure in

any reliability study. More resource (test time and test

units) should be planned for when

an incorrect reliability assessmentcould negatively impact safetyand/or health.


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Reliability EngrsPerspective

Reliability Engineers often refer tothe nines metric.

R=0.999999 would be referred to

as Six Nines reliability.

Unreliability is simply U=1-R

Simplistically, Reliability may bethought of as a measurement ofdesign quality (Material , Margin of

Safety, etc.) over some time period.


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Reliability & Unreliability


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Benefits ofReliability

Engineering

Phase-III


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Why Reliability Engineering? Reliability, Availability, Maintainability, Safety and Quality are what

the Customer says they are, not what the Engineers or the Designerssay they are.

Companies who control the Reliability of their products can only

survive in the business in future as todays consumer is more

intelligentand product aware.

Liability for unreliable products can be very high.

Complexity of products is ever increasing and thus challenge to

Reliability Engineering is also increasing.

Products are advertised by their Reliability Ratings.

A study, in the 80s, showed that when a customer is satisfied with aproduct he might tell 8 other people, whereas dissatisfied customerwill tell 22 people. It would be interesting to repeat this today.

Reliability is Money!


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Why Reliability Engineering?


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Why Reliability Engineering?


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Why do Engg Items Fail?

Designed to Fail Manufactured to Fail

Assembled to Fail Screened to Fail

Stored to Fail

Transported to Fail

Operated to Fail


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Why do Engg Items Fail? The design might be inherently incapable.

The item might be overstressed in some way. Failures might be caused by Variation.

Failures can be caused by wear out.

Failures can be caused by other time dependent

mechanisms (Battery run down, high temp & stress). Failures can be caused by sneaks.

Failures can be caused by errors , such as incorrectspecifications.

There are many other causes of failures:-Gears might be noisy.Oil seals might leak.Display screens might flicker.Operating instructions might be wrong or ambiguous.

Effect of Electromagnetic Interference (EMI).


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FailuresAs Reliability Engineering is concerned

with analyzing failures and providing feedbackto design and production to prevent futurefailures, it is only natural that a rigorousclassification of failure types must be agreedupon.

Reliability engineers speak of:

Failures Causes (External to the system)Failure Modes

Failure Mechanisms (Internal to system)


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Failures FAILURE CAUSE: Circumstances during design,

production or use, that eventually results in a failureof the item.

FAILURE MODE: It is the observed result of a failure.For electrical and electronic components the

following failures modes will be typical. Open Circuits

Short Circuits

Parameter Degradation

Excessive Noise

FAILURE MECHANISM: It is the physical, chemical,metallurgical or other process which results in afailure.


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Failures in Time

Early Failures Chance Failures

Wear out Failures

E i t Lif C


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Equipment Life Curve

Time

Infant

Active

Wearout

What walks on four in the morningtwo at noon and three in the evening ?

= Failure rate

E i t Lif C


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Equipment Life Curve

Infant: Failures are due toproblems in workmanship,process and parts

Active: Failures are caused byextrinsic factors

Wear out: Failures are caused byintrinsic factors


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Bath Tub Curve


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Bath Tub CurvePhase Failure

Rate

Possible Causes Improvement

Actions

Burn-in Decreasing

(DFR)

Manufacturing Defects:

Welding, soldering,

assembly errors, part

defects, poor QC, Poorworkmanship

Better QC,

Acceptance testing,

Burn-in testing,

screening, Highly

Accelerated Stress

Screening

Useful

Life

Constant

(CFR)

Environment, random

loads, Human errors,

Acts of God, chance

events

Excess strength,

redundancy, robust

design

Wear Out Increasing

(IFR)

Fatigue, Corrosion,

Aging, Friction

Derating, preventive

maintenance, parts

replacement, better

material, improved

designs, technology.


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Reasons for Poor Reliability

Poor Design Wrong Manufacturing Techniques

Product Complexity

Poor Maintenance

Organizational Rigidity

Human Errors


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How do we Eliminate Failures?

Meticulous R&M Planning

Rigorous Application ofR&M Techniques

Effective R&M Reviews

Si Si & DFRM


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Failures

Time

Without 6s, DFSS or DFRM

DFSS + 6s

DFRM + DFSS and 6s

Six Sigma & DFRM


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Reliability Engg: Objectives To prevent or to reduce the likelihood or

frequency of failures.

To identify & correct the causes of failuresthat do occur, despite the efforts to

prevent them.

To determine ways of coping withfailures that do occur, if their causes

have not been corrected. To apply methods for estimating the

likely reliability of new designs, and for

analysing reliability data.


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Reliability Engg: BenefitsMatching the capabilities of Product

Design to meet Customer Expectations.

Avoiding Wasted Time due tounanticipated failures inProducts/Services.

Applying predictive & preventive

Maintenance Programs the reducedowntime.

Optimizing Product Burn-in times &

Conditions.


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Reliability Engg: BenefitsMinimizing Distribution Systems Costs.

Optimizing Warranty Costs.

Reducing injuries & loss of life related

to Product failure/liability.

Reducing the loss of property due toequipment failure.

Staffing the team with qualifiedprofessionals (reducing redesign &rework cost).


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Reliability inProduct/Process

Development

Phase-IV


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Reliability-Product/Process Devp Reliability of products is a result of various key functions

working together during development of new products andprocesses.

Various activities to assure reliable products includeactivities such as: Capturing voice of customer, Design

Reviews, Design Failure Modes and Effects Analysis(DFMEA),Design Analysis, Simulation Studies, Optimizationof product and process parameters to deliver consistentproducts, Reliability Testing and Validation, ReliabilityGrowth Studies,Process Capability Evaluation.

Performing these activities require teamwork of manyorganizational functions such as marketing, design,development, suppliers, manufacturing, service and quality.

Engineering Based


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ProductManager

QAManager

Procedure& Audit

QC DataAnalysis

MarketingManager

EngineeringManager

DesignReliability

Engineering

Parts Evaluation& Failure Analysis

StatisticalEngineering

EnvironmentalTest

Design

Assurance

Development

OtherManagers

Production

Manager

ProductionTest &

Inspection

Engineering BasedReliability Organization

T f P j t i BEL


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Types of Projects in BEL

In House Development Projects Joint Development Projects

with DRDO & other National

Labs TOT Projects Design Outsourcing

NOTE: R&M Requirements are an input totheDesign & Development Planning in allthe four types of projects (BEL R&D Manual)

R&M Planning


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R&M Planning

Integral Part of Design Planning

Identification of R&M Tasks

Responsibility Allocation

Documenting the R&M Plan Is Product Specific

i if l h


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Design Life Cycle Phases

Conceptual Phase

Design Phase

Engineering Phase

Manufacturing Phase

Deployment Phase

Conceptual Phase


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Conceptual Phase

Quality Function Deployment (QFD) Setting R&M Goals

Preparation of R&M Plan Trade off analysis

Review

Design Phase


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Design Phase Part Control

Derating / Thermal Design

EMI/ESD Control

Reliability Prediction

FMECA

Designing for Manufacture

Software Quality Planning

Review

Engineering Phase


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Engineering Phase

Derating Verification

Reliability Prediction

Maintainability Prediction

Spare Part Prediction EMC/ESD Evaluation

Environmental Stress Testing

ESS Plan

Software Evaluation

Review

Manufacturing Phase


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Manufacturing Phase

ESD Control ESS DOE SPC Corrective Action

Review

Deployment Phase


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Deployment Phase

QFD Review Analysis of field failure data Corrective Action

Updating FMECA andSpares Prediction

Final R&M Report Review

R&M Plan


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R&M Plan Brief Description of the Product

Functional Block Diagram Design Approach Application Environment

Market Potential Customer R&M Goals

R&M Phases R&M Tasks/Responsibilities Data Collection System (FRACAS) Preparation of R&M Report

R&M Techniques


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R&M Techniques Quality Function Deployment

Part Control & Derating Thermal Design and Analysis Redundancy

EMI / ESD Control DFMM Reliability Prediction Maintainability Prediction Spare Part Prediction FMEA and FMECA ESS, HALT & HASS

Corrective Action

DFRM Road Map


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DFRM Road Map

ConceptualizeDesign

Engineer

Freeze

Product /System Realisation


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Product /System RealisationProject Management Design Phases

Production Information/ Documentation Phase

Evaluation Phase

Design RealisationPhase

Product / SystemDesign Phase

Conceptual Phase

Project Planning,

Execution Tracking,Progress Reviews,

Resource Monitoring,

Communications,

Risk Management,

Procurement Tracking,

Amendment Sanction

Project Initiation, Planning,Proposal & Sanction

Project Closure

Reliability Program Flow


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Reliability Program FlowASPECTS TO CONSIDER TASKS METHODS

Project / Contract Requirements,

Markets,

Competition,

Technology Knowledge

Risks, Costs


Environments, Stresses

Variation,

Tools, Methods,Skills, Training,

Suppliers,

Value / Cost


Environments, Stresses

Variation,Methods,

Test Items, Numbers Levels

Manufacturing,

Facilities,

Suppliers,

SPECIFICATION

Performance, Cost,Reli abil ity / Dur abil ity/ Safety

DESIGNCreate (Product, Processes)

Analyse (Performance,

Reliability)Refine / Improve

QFD

SpecificationReview

DEVELOPMENTTEST PLAN

Create

Design Review

RELIABILITY/DURABILITY

TESTS

PERFORMANCECONFORMITY

TESTS

Synthesis, Models CAD/CAE/EDA

FEA, CFD Simulation

(EDA, Monte Carlo)

FMEA, FTA, etc.DOE, Taguchi

Maintenance, RCM

Design Review

Performance, Conformity

HALT, DOE, TaguchiStandard M ethods, FRACAS,

Data Analysis, Main tenance,

RCM

Final Design

Production

Design Reviews


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DesignReviews Design reviews are regularly scheduled meetings led

by the design function. It must include otheraffected areas

Design reviews is an effective method to preventproblems and misunderstandings.

Design reviews are series of verification and designevaluation activities that are more than anengineering inspection

Design reviews must include:

Design / Functional requirement considerationsFormal reliability and confidence goals

Component sub-system duty cycles

Computer simulation and bench test results

Design Review Committee


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Design Review CommitteeMember Role

Chairperson (sometimesdesign leader) Chair the meeting and ensure compliance to agenda, time management

Design leader

(usually chairperson)

Presents the design concept, features and details

Quality Engineer Represents the customer and provides input on design

Materials Engineer Reviews selection of material, process requirements ( such as heattreatment), comments on availability of standard materials ( such as

alloy steel)

Manufacturing Engineer

( if applicable)

Considers current process capabilities and provides input on feasibility

Supplier ( if applicable) Considers current process capabilities and provides input on feasibility

CAD / Applied

Mechanics Analysis

Plans for appropriate analysis and later shares analysis results and

gives recommendation for changes if any

Reliability Engineer Evaluates the designs, interprets the test and analysis reports with

reference to reliability goals

Safety Engineer Reviews and ensures that safety requirements are addressed

P d t & P D


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Product & Process Devp

Mean time between failure (MTBF)values for existing products can bedetermined and reasonable goals

established.MTBF values for components and

purchased parts can be determined.

Failure types and times ofoccurrence can be anticipated.

P d t & P D


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Product & Process Devp

Optimal break-in/burn-in timescan be determined.

Recommendations for warranty

times can be established.

The impact of age and operatingconditions on the life of theproduct can be studied.

The effects of parallel or redundant

design features can be determined.

P d t & P D


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Product & Process DevpAccelerated life testing can be used

to provide failure data.

Field failure data can be analyzed to

help evaluate product performance.Concurrent engineering can improve

the efficiency & effectiveness ofproduct development by schedulingdesign tasks in parallel rather thansequentially.

P d t & P D


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Product & Process DevpReliability engineering can provide

information to individual teams aboutfailure rates of their proposedcomponents.

Cost accounting estimates can beimproved through the use of lifecycle

cost analysis using reliability data.When management employs FMEA

techniques, reliability engineering

provides essential input.

V


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Liability &

Warranty

Management

Phase-V

Product Liability


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A liability can mean something that is a

hindrance or puts an individual or group at adisadvantage, or something that someone isresponsible for, or something that increasesthe chance of something occurring (i.e. it is acause). Liability may refer in specific to:

1. Negligence-Legal

2. Strict Liability-Legal3. Breach of WarrantyLegal4. Defects5. Failure to Warn

Product Liability

Negligence


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Negligence1. Product manufacturers owe a

duty of care to Customer.2. The standards for that care havebeen breached.

3. As a result a compensable injuryresults.4. There are damages or injury to

the plaintiff.

Ex: Sharp edges, Screws protruded out,open manholes without any sign board

Breach of Warranty


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Warranties are violated when the promise

is broken or the goods are not asexpected. The seller may honor thewarranty by making a refund or a

replacement.1. The product is defective or dangerous.2. Risk is too high (risk/benefit higher

than competition, etc.)Ex: Honda Cars with faultyhoses, gas pedal,foot mat etc.

Breach of Warranty

Strict Liability


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1. Implied Merchantability2. Implied Warranty for particularpurpose (pacemaker, lawnmower

may be excluded by seller)

3. Breach of express warranty

(written or oral contract:cures 100%)

Strict Liability

Defect


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1. Actual Defect (sharp edges,)

2. Consumer Expectations/Seller

Knowledge.

3. Risk / Benefit

4. Defective Warnings5. Inadequate Guarding

Defect

Failure to Warn


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You have a duty to warn. If you do notwarn that coffee is hot, you are likelyto get in trouble

Failure to Warn

Liability Management


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Often users seek liability damages

because a product creates a risk that thecompany could not predict during thedesign and manufacturing efforts.

Product traceability helps a company tolocate products in the hands of the user.

Often, a company finds that they have a

need to provide additional user hazardinformation, modify or recall productsfor newly uncovered user hazards.

Liability Management

Warranty


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Warranty is a statement of assurance or

undertaking issued by the manufacturerof a product w.r.t. the performance ofthe product and parts supplied for a

certain period of time as stated in thewarranty card.

It means replacement or repair of the

defective product/part in the stated timeperiod by the supplier/ manufacturer.

Warranty

Product Warranty


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The basic customer requirementsfor a product Warranty are:

The warranty is Full or

Limited. The information is simple, clear

and easy to understand.

The warranty is available to thecustomer before purchase.

Product Warranty

Warranty Types


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Implied Warranty: Product will perform

upon sale.

Express Warranty: Created by thewords/actions of the seller.

Full Warranty: Full service warranty.

Extended Warranty:Add on (sold along).

Deceptive Warranty: False Promise.As-is Warranty: Sold with faults

(What you see, is what you get)

Warranty Types

Warranty Management


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Warranty Management Traditional View:Considered as Cost of

providing Customer Satisfaction. 4-5%of total sales revenue per annum.

Modern View: Many realized the

potential of underlying value inWarranty Mgt.

Latest View: Warranty Management is

considered as a Separate RevenueStream. It can provide a competitiveedge. (Tools: ALT, FMEA to build high

Reliability in Design of products)

Phase VI


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Customer Needs

& Supplier

Reliability

Phase-VI

CUSTOMER


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CUSTOMER

There is only one BOSS-The Customer.He can FIREeverybody in the Company

From the CHAIRMAN.on down-Simply by-

SPENDING HIS MONEY SOMEWHERE ELSE.

-Sam Walton

Customer Expectations


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Customer Expectations

High Reliability

Low Life Cycle Cost

Reliability Linked WarrantyReliability Centered Maintenance

Reliability DemonstrationLogistic Support Analysis

Customer Needs Assessment


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Reliability Requirements: These requirements

must have the following attributes: Measurable Attainable

Keyed to customer desires Requirements must be measurable so that

they can be verified during the design processand after fielding the device.

Reliability requirements may be specified bythe customer or generated by the designteam.

Customer Needs Assessment

Customer Requirements


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Three methods of determining customerrequirements include:

1. Marketing surveys2. Benchmarking and

3. Prototyping with beta testing.4. Quality Function Deployment (QFD).

Customer surveys are used to determine

what customers want by asking them. Surveys should be designed to obtain the

maximum information about the customersdesires.

Customer Requirements

Benchmarking


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Process Benchmarking: It focuses on discrete

work processes and operating systems.

Performance Benchmarking: It focuses onelements of price, technical quality, features,speed, reliability, etc.

Project Benchmarking: Project constraint factors

are time, cost, resources& performance. Project bench marking is used to select new

techniques for planning, scheduling, andcontrolling projects.

Benchmarking

Prototyping


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yp gPrototyping is a process that enables the developer to create a designin an evolutionary manner. The sequence of events would be:-

Beta Testing


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Beta Testing Beta testing can be considered a form of

external user acceptance testing. Versions of the software, known as beta

versions, are released to a limited audienceoutside of the programming team.

The software is released to groups ofpeople so that further testing can ensurethe product has few faults or bugs.

Sometimes, beta versions are madeavailable to the open public to increase thefeedback field to a maximal number offuture users.

QFD


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QFDQFD is a system/tool for translating

customer requirements into appropriatecompany requirements at each stage fromResearch and Product development to

Engineering and Manufacturing toMarketing/Sales and distribution.

Methodology having high customer focus

Assists in the planning processes forproducts/services. The voice of the customer is the driver for

the development of requirements (for the

new or revised product or service).

House of 7


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Objective Statement

Customer Needsrequirement of

WHATS ?

ImportanceratingofWHATS

Relation shipMatrix between

HOWs? WHATs?

Technical Competitive

Assessment of HOWs or How

Much?

Target Goals of HOWS ?

Correlation Matrixof HOWS?

Technical descriptors of HOWS ?

Cu

stomerassessmentof

competitors

Quality

1 2

3

45

6

6

QFD


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Q

QFD - Benefits


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Q Fewer & Earlier Changes

Shorter Development Time

Fewer Start-up Problems

Lower Start-up Costs

Warranty Reduction

Customer Satisfaction

Knowledge Transfer

Supplier Reliability


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An effective Supplier ReliabilityProcess is important to the procurementof key/ critical components, material,

assemblies and sub systems.It overlaps Procurement Quality &also addresses the specific preparations& monitoring necessary for durable &reliable products. The suggested 12 keysteps are:-



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Step-1: Generate a document thatdescribes basic supplier Productrequirements.

Step-2: Perform an analysis of potentialsupplier capabilities.Step-3: Review the suppliersproposal& examine the details of how they planto conform to the requirements.Step-4: Supplier selection should bebased upon a no of factors. (Best & LCC)



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Step-5:Finalize procurement criteria byworking with the selected supplier.Step-6: Manage the manufacturing

process by having the supplier use toolslike SPC, FRACAS & config control.Step-7: Validate the suppliersprocesses by evaluating Mfg stability &process control over multiple runs.Step-8: Perform a Rel DemonstrationTest that covers both process & product.



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pp yStep-9: Provide component suppliers

feedback and focus on Quality,conformance & Life Cycle Costs.Step-10: Run an internal FRACAS &

document failure modes down to rootcauses for all significant failures.Step-11: Tie sch Prog/Project Design

Reviews together & work more closely.Step-12: Near Completion; Long termdurability / Demo / Rel Growth / abuse

Tests (if indicated). Share the Results.

Phase VII


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Product Life

Cycle & System

Engineering

Phase-VII


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Life Cycle Cost


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e Cyc e Cost

Cost-Reliability Relationship


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Cost Reliability Relationship

Product Life Cycle Engg


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Reliability Growth


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The definition given in MIL-STD-721C for reliabilitygrowth is : The improvement in a reliability parameter

caused by the successful correction of deficiencies initem design of manufacture.

There are techniques by which one may assess thegrowth of reliability. MIL-HDBK-189 identifies detailed

program management and mathematical models thatmay be applied to asses the demonstrated reliabilitycompared to planned reliability progress over time.

The two predominant models that are applied byreliability professionals are :

1. Duane model (developed by James T. Duane)2. US Army Material Systems Analysis Activity(AMSAA) model.

Reliability Plans &


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MIL-HDBK-781A:In order to avoid duplication of testeffort and to ensure that deficiencies are notoverlooked, the integrated reliability test planningshould define procedures which ensure that reliabilitydata is derived from all other tests. Integrated testplanning should consider a description of the test plansselected for use, the decision risks, and theenvironmental test conditions, and should be keyed tothe program life-cycle phases.

The Sequential Test Plan will result in the most rapiddetermination of product reliability at acceptable risklevels. Product development or program schedulesshould also be integrated with the reliability plan and

activit schedule.

Integrated Schedules

Reliability Program


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Six issues which should be considered

for the design of an effective reliabilityProgram are:

1. Definition of Reliability Program.

2. Developing the Reliability Goals andrequirements.

3. Design for Reliability.4. Assessing Reliability Progress.

5. Measuring Reliability.

6 Ensuring Reliable Performance

y g

Design Evaluation


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gThe design process should include periodic evaluationsto assure that the design goals and requirements arebeing met. Design Process Steps are:

During the design input and design output cycle ,thefollowing phases are generally followed :

Phase I: Marketing ResearchPhase II: Concepts

Phase III: DesignPreliminary DesignDetailed Design

Phase IV: Manufacturing EngineeringPhase V: Finalized Design

Design and

Development

Planning

Design

Input

Design

Output

DesignVerification

Design Tools


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gThe design Tools used in the design planning are:

Geometric Dimensioning & Tolerancing (GD&T)Design for Manufacturing / Design for Assembly

Value Engineering

Design of Experiments (DoEs)

FMEA / FMECA

Finite Element Analysis (FEA)

Solid Modeling

Simulation Techniques

Computer Aided Design (CAD)

Computer Aided Engineering (CAE)

Reliability Engineering Plans


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Managing Changing


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RequirementsRequirements may change during specification,design, development, and testing proceeds.Below are the procedures for managing

changing requirements. Submitting requirements change request.

Evaluating requirements change request.

Reviewing requirements change request.

Scheduling changes to product documentsand tests.

Implementing the scheduled changes.

Systems Engineering


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y g gIt is top down approach defining a logical

sequence of activities and decisionstransforming an operational need into adescription of System performance parametersand a preferred system configuration. It

includes the following:-

Mission Requirements Analysis.

Functional Analysis.

Reliability Allocation.

Synthesis.

Logistic Engineering.

Project Development Elements


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j pThe product development process may be viewed as a

trade off between a no of competing projectrequirements as shown below.

Time To

Develop

Development

Cost

Product

Performance

WarrantyCosts (or)Support

ReliabilityGoals

Maintenance& Spares

Cost

Benchmarks of Reliability Practice


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y1. Completely analyze all failures to identify the root

cause of failure and determine the necessary correctiveaction, including redesign and revision of analytical tools.

2. Avoid dedicated reliability demonstration testing. Focuson new components or the integration of old items in a

new way. Emphasize engineering development testing tounderstand and validate the design process and models.Accelerated testing should be used to age high reliabilityitems and to identify their failure mechanisms.

3. Assign responsibility for reliability to a productdevelopment team with the authority to determine thereliability requirements and to select the design, analysis,test, and manufacturing activities needed to achieve thatreliability.

Human Factors AnalysisIt b f d t H E i i i


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It may be referred to as Human Engineering, ergonomics oruser-friendly designs. Human factors analysis focuses on the

man-machine interface. When designing man-machineinterfaces, it is best to take advantage of the usersexpectations. General rules and conventions establish userexpectations.Toggle switches should move up for on and down for off.

Rotating knobs for liquids turn counter-clockwise for on,and clockwise for off.

Electrical equipment is the opposite for liquids, counter-clockwise turns off while clockwise turns on.

Use green as a normal operating indicator, and red asabnormal.

Audio alarms signal an abnormal operation.

In software, users expect the same conventions from allmanufacturers.


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Conclusion


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REMEMBERIF YOU DO WHAT YOUHAVE BEEN DOINGYOU WILL GET WHAT

YOU HAVE BEEN

GETTING.


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AnyDoubtsOR

Questions?


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01-Reliability Management (1)

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