unit iv - maintenance, system reliability & tqm

7/28/2019 Unit IV - Maintenance, System Reliability & TQM

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UNIT - IV

SEMESTER - II


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Strategic Importance of

Maintenance and Reliability

Failure has far reaching effects on a firms

Operation

Reputation

Profitability

Dissatisfied customers

Idle employees

Profits becoming losses

Reduced value of investment in plant andequipment

Equipment Malfunctions have a directimpact on:

Production capacity

Production costs

Product and service quality

Employee or customer safety

Customer satisfaction


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Maintenance and Reliability Objective:

To maintain the capability of the system while controlling costs

Maintenance is all activities involved in keeping a systems equipment in working order

Reliability is the probability that a machine will function properly for a specified time

Important Tactics

Maintenance

1. Implementing or improvingpreventive maintenance

2. Increasing repair capability or speed

3. Measured by MTTR (Mean Time toRepair)

Reliability

1. Improving individual components

2. Providing redundancy

3. Measured by MTBF (Mean Time

Between Failures)


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Approaches to Improving

Machine Reliability

Overdesign - enhancing the machine

design to avoid a particular type of

failure

Design simplification - reducing thenumber of interacting parts in a machine

Redundant components - building

backup components right into the

machine so that if one part fails, itsautomatically substituted


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Rs

R3

.99

R2

.80

Reliability Example

R1

.90

Reliability of the process is

Rs= R1 x R2 x R3 = .90 x .80 x .99 = .713 or 71.3%

where R1 = reliability of component 1

R2 = reliability of component 2

and so on

Rs= R1 x R2 x R3 x xRn

Improving individual components

Reliability


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Overall System Reliability

Reliabilityofthesystem(percent)

Average reliability of each component (percent)

| | | | | | | | |

100 99 98 97 96

100

80

60

40

20

0


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Product Failure Rate (FR)

Basic unit of measure for reliability

FR(%) = x100%Number of failuresNumber of units tested

FR(N) =Number of failures

Number of unit-hours of operating time

Mean time between failures

MTBF =1

FR(N)

Providing Redundancy

Provide backup components to increase reliability

+ xProbability of

first componentworking

Probability ofneeding second

component

Probability ofsecond

component

working


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How Maintenance is Performed

OperatorMaintenancedepartment

Manufacturers field

serviceDepot service

(return equipment)

Preventivemaintenance costs less andis faster the more we move to the left

Competence is higher as wemove to the right

Maintenance Two types of maintenance

1. Preventive maintenance routine inspection and servicing to keep facilities ingood repair

2. Breakdown maintenance emergency or priority repairs on failed equipment

Implementing Preventive Maintenance

Need to know when a system requires service or is likely to fail

High initial failure rates are known as infant mortality

Good reporting and record keeping can aid the decision on when preventivemaintenance should be performed


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Maintenance Activities

Repairs

Repair activities are reactive.

Breakdowns and malfunctions typically occur when equipment is inuse.

Standby machines and parts can speed repairs.

Preventive Maintenance (PM)

Regularly scheduled inspections are performed.

PM activities are performed before equipment fails.

PM is usually performed during idle periods.


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Maintenance Strategy

Employee Involvement

Information sharing

Skill training

Reward system

Employee empowerment

Maintenance and Reliability Procedures

Clean and lubricate

Monitor and adjust

Make minor repair

Keep computerized records

Results

Reduced inventory

Improved quality

Improved capacity

Reputation for quality

Continuous improvement

Reduced variability


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Computerized Maintenance System

Output Reports

Inventory andpurchasing reports

Equipment

parts list

Equipmenthistory reports

Cost analysis(Actual vs. standard)

Work orders

Preventivemaintenance

Scheduleddowntime

Emergencymaintenance

Data entry Work requests

Purchaserequests Time reporting Contract work

Data Files

Personnel datawith skills,wages, etc.

Equipment filewith parts list

Maintenanceand work order

schedule

Inventory ofspare parts

Repairhistory file


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Totalcosts

Breakdownmaintenance

costs

Costs

Maintenance commitment

Traditional View

Preventivemaintenancecosts

Optimal point (lowestcost maintenance policy)

Maintenance Costs

To balance preventive and breakdown maintenance costs


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How Speedy Should Repairs Be?

Cost ($)

Speed of Making Repairs

0

Minimum

Total Cost

of Repairs

Cost of RepairCrews & Shops,Spare Parts, and

Standby Machines

Cost ofInterruptions toProduction

Total Costsof Repairs

Slow Fast


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Increasing Repair Capabilities1. Well-trained personnel

2. Adequate resources

3. Ability to establish repair plan and priorities

4. Ability and authority to do material planning

5. Ability to identify the cause of breakdowns

6. Ability to design ways to extend MTBF


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Establishing Maintenance Policies Simulation

Computer analysis of complex situations

Model maintenance programs before they are implemented

Physical models can also be used

Expert systems

Computers help users identify problems and select course of action

Total Productive Maintenance (TPM)

Designing machines that are reliable, easy to operate, and easy to maintain

Emphasizing total cost of ownership when purchasing machines, so that service andmaintenance are included in the cost

Developing preventive maintenance plans that utilize the best practices ofoperators, maintenance departments, and depot service

Training workers to operate and maintain their own machines


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Secondary Maintenance Responsibilities

Housekeeping, grounds keeping

New construction, remodeling

Painting

Security, loss prevention

Pollution control

Waste recycling

Safety equipment maintenance

Public hazard control

Trends in Maintenance

Production machinery is becoming more and more complex and maintenancepersonnel must keep pace

Special training programs to maintain worker skill level

Subcontracting service companies

Production workers maintain own equipment

Computer assistance in maintenance


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Computer Assistance in Maintenance

Scheduling maintenance projects

Maintenance cost reports by production department, cost category, and other

classifications Inventory status reports for maintenance parts and supplies

Parts failure data

Operations analysis studies

Maintenance Issues in Service Organizations Maintenance issues are not limited to manufacturing

Transportation firms (airlines, trucking companies, package delivery services,

railroads) must keep their vehicles in top operating condition

Highway departments must maintain roadways

Office personnel are reliant on copiers, printers, computers, and fax machines

working properly

As services become increasingly automated, service firms face more and more

maintenance issues


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Determinants of Quality

Service

Ease of

use

Conforms

to design

Design

Quality is fitness for use

(Joseph Juran)

Quality is conformance to requirements

(Philip B. Crosby)

What is quality?

Quality, simplistically, means that a product should meet its specification.

Quality is the ability of a product or service to consistently meet or exceed customer

expectations.

At a Time and over a period of time.


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Quality management activities Quality assurance

Establish organisational procedures and standards for quality.

Quality planning

Select applicable procedures and standards for a particular project and modifythese as required.

Quality control

Ensure that procedures and standards are followed by the softwaredevelopment team.

Dimensions of Quality

Performance - main characteristics of the product/service

Aesthetics - appearance, feel, smell, taste

Special Features - extra characteristics

Conformance - how well product/service conforms to customers expectations

Reliability - consistency of performance

Durability - useful life of the product/service

Perceived Quality - indirect evaluation of quality (e.g. reputation)

Serviceability - service after sale


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Service Quality

Tangibles

Convenience

Reliability

Dimension Examples

1. Tangibles Were the facilities clean, personnel neat?2. Convenience Was the service center conveniently located?

3. Reliability Was the problem fixed?

4. Responsiveness Were customer service personnel willing and able to

answer questions?

5. Time How long did the customer wait?

6. Assurance Did the customer service personnel seem

knowledgeable about the repair?

7. Courtesy Were customer service personnel and the cashier

friendly and courteous?

Responsiveness

Time

Assurance

Courtesy


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The Consequences of Poor

Quality

Loss of business

Liability

Productivity

Costs

Top management

Design

Procurement

Production/operations

Quality assurance

Packaging andshipping

Marketing and sales

Customer service

Responsibility for Quality

Quality plan structure

Product introduction;

Product plans;

Process descriptions;

Quality goals;

Risks and risk management.

Quality plans should be short, succinct

documents

If they are too long, no-one will read

them.

Quality plans

Quality reviews A group of people carefully examine part or all of a

software system and its associated documentation.

Code, designs, specifications, test plans, standards, etc.

can all be reviewed.

Software or documents may be 'signed off' at a review

which signifies that progress to the next development

stage has been approved by management.


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Costs of Quality Failure Costs - costs incurred by defective parts/products or faulty services.

Internal Failure Costs Costs incurred to fix problems that are detected before the product/service

is delivered to the customer.

External Failure Costs

All costs incurred to fix problems that are detected after theproduct/service is delivered to the customer.

Appraisal Costs

Costs of activities designed to ensure quality or uncover defects

Prevention Costs

All TQ training, TQ planning, customer assessment, process control, and

quality improvement costs to prevent defects from occurring

1924 - Statistical process control charts

1930 - Tables for acceptance sampling

1940s - Statistical sampling techniques

1950s - Quality assurance/TQC

1960s - Zero defects

1970s - Quality assurance in services

Evolution of

Quality Management


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Cost of Poor Quality Category Examples

Failure Costs Internal Prevention Costs

Re-shipping Quality Administration

Unnecessary Travel Time Quality Planning

Re-picking/Picking Quality Systems Design

Unpacking/Storing Returns Calibration and MaintenanceRe-order Time Production/Inspection Equipment

Crediting Time Vendor Assessment

Quality Training

Failure Costs External Appraisal Costs

Loss of Sales Incoming Test and Inspection

Complaints In-Process Inspection

Returns Final Inspection

Warranty Claims Sampling Procedures

Quality Audits

Costs of Quality


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Standards are the key to effective quality management.

They may be international, national, organizational or project standards.

Product standards define characteristics that all components should exhibit e.g. acommon programming style.

Process standards define how the software process should be enacted.

Quality assurance and standards

Encapsulation of best practice- avoids repetition of past mistakes. Framework for quality assurance processes - they involve checking compliance to

standards.

Provides continuity - new staff can understand the organisation by understandingthe standards that are used.

Importance of standards

They may not be seen as relevant and up-to-date by software engineers.

They often involve too much bureaucratic form filling.

If they are unsupported by software tools, tedious manual work is often involved to

maintain the documentation associated with the standards.

Problems with standards


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Malcolm Baldrige National Quality Award

1.0 Leadership (125 points)

2.0 Strategic Planning (85 points)

3.0 Customer and Market Focus (85 points)

4.0 Information and Analysis (85 points)

5.0 Human Resource Focus (85 points)

6.0 Process Management (85 points)

7.0 Business Results (450 points)

The Deming Prize

Honoring W. Edwards Deming

Japans highly coveted award

Main focus on statistical quality

control

Continuous ImprovementPhilosophy that seeks to make never-ending improvements to the process of convertinginputs into outputs.

Kaizen: Japanese

word for continuous improvement.


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International Organization for Standardization (ISO) - mission is to promote the

development of standardized products to facilitate trade and cooperation across

national borders.

Representatives from more than 146 nations.

ISO 9000 series of standards sets requirements for quality processes.

Nearly half a million ISO 9000 certificates have been awarded to companies around

the world.

ISO 14000 series also sets standards for operations that minimize harm to the

environment.

Standards
http://www.iso.org/iso/en/iso9000-14000/index.htmlhttp://www.iso.org/iso/en/iso9000-14000/index.htmlhttp://www.iso.org/iso/en/iso9000-14000/index.html


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ISO Standards ISO 9000

Set of international standards on quality management and quality assurance,critical to international business

Series of standards agreed upon by the International Organization forStandardization(ISO)

Adopted in 1987

More than 100 countries

A prerequisite for global competition

ISO 9000 directs you to:

document what you do and then do as you documented.

9001

Model for Quality Assurance in Design, Production Installation, and Servicing.

9002

Model for Quality Assurance in Production and Installation

9003

Model for Quality Assurance in Final Inspection Test


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ISO Standards ISO 14000

A set of international standards for assessing a companys environmental

performance

Standards in three major areas

Management systems

Operations

Environmental systems

Particularly important - documents are the tangible manifestation of the software.

Documentation process standards

Concerned with how documents should be developed, validated and maintained.

Document standards

Concerned with document contents, structure, and appearance.

Document interchange standards

Concerned with the compatibility of electronic documents.

Documentation standards


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Documentation process


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This involves checking the software development process to ensure that procedures

and standards are being followed.

There are two approaches to quality control

1. Quality reviews;

2. Automated software assessment and software measurement.

Total Quality Management

A philosophy that involves everyone in an organization in a continual

effort to improve quality and achieve customer satisfaction.


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What is TQM?

Constant drive for

continuous

improvement and

learning.

Concern foremployee

involvement and

development

Management by

Fact

Result Focus

Passion to deliver

customer value /

excellence

Organisation

response ability

Actions not just words

(implementation)Process

Management

Partnership

perspective

(internal /

external)


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Learning

LEARNING AND TQM

Process Improvement

Quality Improvement

Customer

SatisfactionShareholder

Satisfaction

Employee

Satisfaction


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BASIC PRINCIPLES OF TQM

Approach Management Led

Scope Company Wide

Scale Everyone is responsible for Quality

Philosophy Prevention not Detection

Standard Right First Time

Control Cost of Quality

Theme On going Improvement


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QC Throughout Production Systems

Raw Materials,Parts, and

Supplies

ProductionProcesses

Products andServices

Inputs Conversion Outputs

Control Chartsand

Acceptance Tests

Control Chartsand

Acceptance TestsControl Charts

Quality ofInputs

Quality ofOutputs

Quality ofPartially Completed

Products

Throughput:

Output relative to input; the amount passing through a system from input to output over a

period of time


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1. Find out what the customer wants

2. Design a product or service that meets or exceeds customer wants

3. Design processes that facilitates doing the job right the first time

4. Keep track of results

5. Extend these concepts to suppliers

The TQM Approach

1. Continual improvement

2. Competitive benchmarking

3. Employee empowerment

4. Team approach

5. Decisions based on facts6. Knowledge of tools

7. Supplier quality

8. Champion

9. Quality at the source

10. Suppliers

Elements of TQM

1. Management Support

2. Mission Statement

3. Proper Planning

4. Customer and Bottom Line Focus

5. Measurement

6. Empowerment

7. Teamwork/Effective Meetings

8. Continuous Process Improvement

9. Dedicated Resources

Elements for Success


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A good or service free of deficiencies.

Poor quality can account for 20% loss in revenue.

Benchmarking is the process of analyzing other firms best practices.

Quality control is measuring goods and services against established quality standards.

Many companies evaluate quality using the Six Sigma concept.

A company tries to make error-free products 99.9997% of the time, a tiny 3.4

errors per million opportunities.

Importance of Quality

Correlation

matrix

Design

requirements

Customer

require-

ments

Competitive

assessmentRelationship

matrix

Specificationsor

target values
http://www.motorola.com/content.jsp?globalObjectId=3079http://www.motorola.com/content.jsp?globalObjectId=3079


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Measurement

Muem

Muem

Measurement

Empowerment/Shared Leadership

ProcessImprovement/

ProblemSolving

TeamManagement

CustomerSatisfactio

nBusinessResults

The Continuous Improvement Process


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Modern History of Quality Management Frederick W. Taylor wrote Principles of Scientific Management in

1911.

Walter A. Shewhart used statistics in quality control and inspection,and showed that productivity improves when variation is reduced(1924); wrote Economic Control of Manufactured Product in 1931.

W. Edwards Deming and Joseph M. Juran, students of Shewhart,

went to Japan in 1950; began transformation from shoddy toworld class goods.

In 1960, Dr. K. Ishikawa formalized quality circles - the use of smallgroups to eliminate variation and improve processes.

In the late 70s and early 80s:

Deming returned from Japan to write Out of the Crisis,

and began his famous 4-day seminars in the United States

Phil Crosby wrote Quality is Free

NBC ran If Japan can do it, why cant we?

Motorola began 6 Sigma

Hi t f Q lit M t


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History of Quality ManagementDemings Concept of Profound Knowledge

Understanding (and appreciation) of Systems

- optimizing sub-systems sub-optimizes the total system

- the majority of defects come from systems, the responsibility

of

management (e.g., machines not in good order, defective material,

etc.

Knowledge of Statistics (variation, capability, uncertainty in data,

etc.)

- to identify where problems are, and point managers and

workers

toward solutions

Knowledge of Psychology (Motivation)

- people are afraid of failing and not being recognized,

so they fear how data will be used against them

Theory of Knowledge

- understanding that management in any form is a prediction,

and is based on assumptions


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Demings 14 Points

1. Create constancy of purpose for improvement2. Adopt a new philosophy

3. Cease dependence on mass inspection

4. Do not award business on price alone

5. Work continually on the system of production and

service6. Institute modern methods of training

7. Institute modern methods of supervision of workers

8. Drive out fear

9. Break down barriers between departments

10. Eliminate slogans, exhortations, and targets for thework force

11. Eliminate numerical quotas

12. Remove barriers preventing pride of workmanship

13. Institute a vigorous program of education and retraining

14. Take action to accomplish the transformation

History of Quality Management


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What is Six Sigma?

Statistically

Having not more than 3.4 defects per million

Conceptually

Program designed to reduce defects

Requires the use of certain tools and techniques

A goal of near perfection in meeting customer requirements

A sweeping culture change effort to position a company for greater customer

satisfaction, profitability and competitiveness A comprehensive and flexible system for achieving, sustaining and maximizing

business success; uniquely driven by close understanding of customer needs,

disciplined use of facts, data, and statistical analysis, and diligent attention to

managing, improving and reinventing business processes

Si Si I t M th d


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Six Sigma Improvement MethodsDMAIC vs. DMADV

Define

Measure

Analyze

Design

Verify

Improve

Control

Continuous Improvement Reengineering

Six Sigma Programs


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Six Sigma Programs

Six Sigma programs

Improve quality

Save time

Cut costs

Employed in

Design

Production

Service

Inventory management

Delivery

Providing strong leadership

Defining performance merits

Selecting projects likely to succeed

Selecting and training appropriate people

Six Sigma Management

Six Sigma Technical

Improving process performance

Reducing variation

Utilizing statistical models

Designing a structured improvement strategy

Six Sigma Team

Top management

Program champions

Master black belts

Black belts

Green belts

Ob t l t I l ti TQM


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Lack of:

Company-wide definition of quality

Strategic plan for change

Customer focus

Real employee empowerment

Strong strong motivation

Time to devote to quality initiatives

Leadership

Poor inter-organizational communication

View of quality as a quick fix

Emphasis on short-term financial results

Internal political and turf wars

Obstacles to Implementing TQM

Basic Steps in Problem

Solving

Define the problem andestablish an improvement goal

Collect data

Analyze the problem

Generate potential solutions Choose a solution

Implement the solution

Monitor the solution to see if itaccomplishes the goal

Process Improvement


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Process Improvement: A systematic approach to improving a process

1. Process mapping

2. Analyze the process3. Redesign the process

Process Improvement

Process improvement - a systematic approach to improving a process Process mapping

Analyze the process

Redesign the process

Tools

There are a number of tools that can be used for problem solving and processimprovement

Tools aid in data collection and interpretation, and provide the basis for decisionmaking

Process Improvement and Tools


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PLAN

CHECK

DOACT

The Deming Cycle or PDCA Cycle

Plan a change to the process. Predict the effect this

change will have and plan how the effects will be

measured

Implement the change on a small

scale and measure the effectsAdopt the change as a

permanent modification to

the process, or abandon it.

Study the results to learn what

effect the change had, if any.

Quality Management Process

h l


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The Process Improvement Cycle

Implement the

Improved process

Select a

process

Study/document

Seek ways to

Improve it

Design an

Improved process

Evaluate

Document


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Basic Quality Tools

Flowcharts Check sheets

Histograms

Pareto Charts

Scatter diagrams

Control charts

Cause-and-effect diagrams

Run charts

Flow Chart Example:


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Flow Chart Example:Self-Serve Gas Before Improvement

Drive incheck price

self serve?to pump

shut offengine

walk to paystation

yes

no

check card transmit approved? turn on

pump

yes

no

back

to car

pump

gas walk tobooth

wait

employee

totals

charges

check

accuracy

prepare

receipt

sign

copy

copy to

file

copy to

wallet

return to car

on the road

again

Ch k Sh


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Check Sheet

Billing Errors

Wrong Account

Wrong Amount

A/R Errors

Wrong Account

Wrong Amount

Monday

P A l i


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Pareto Analysis

80% of theproblems

may be

attributed to

20% of thecauses.

Smeared

print

N

umberofde

fects

Off

center

Missing

label

Loose Other

C l Ch


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Control Chart

970

980

990

1000

1010

1020

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

UCL

LCL

Lower

Control

Limit

Upper

Control

Limit

C d Eff t Di


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Cause-and-Effect Diagram

Effect

MaterialsMethods

EquipmentPeople

Environment

Cause

Cause

Cause

Cause

Cause

CauseCause

Cause

CauseCause

Cause

Cause

R Ch t


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Run Chart

Time (Hours)

Diameter

T ki I t


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Tracking Improvements

UCL

LCL

LCLLCL

UCLUCL

Process not centered

and not stable

Process centered

and stable

Additional improvements

made to the process

M th d f G ti Id


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Methods for Generating Ideas

Brainstorming

Quality circles

Interviewing

Benchmarking

Benchmarking Process Identify a critical process that needs improving

Identify an organization that excels in this process

Contact that organization

Analyze the data

Improve the critical process

5W2H - What, When, Where, Why, Who, How, HowMuch


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Acceptance Sampling is a form of inspection applied to lots or batches of items

before or after a process to judge conformance to predetermined standards.

Acceptance Sampling is very useful when:

Large numbers of items must be processed in a short amount of time.

The cost of passing defectives is low.

Fatigue/boredom is caused by inspecting large numbers of items.

Destructive testing is required

Advantages

Less expensive

Reduced damage

Reduces the amount of inspection error

Disadvantages

Risk of accepting bad lots and rejecting good lots

Less information generated

Requires planning and documentation

Sampling Plans


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Sampling Plans

Sampling Plans specify the lot size, sample size, number of samples and

acceptance/rejection criteria.

Sampling plans involve:

1. Single sampling

2. Double sampling

3. Multiple sampling

Random

sample

Lot

1 Single Sampling Plans


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1.Single Sampling PlansA single sampling plan is one where:

A representative sample of n items is drawn from a lot size of N items

Each item in the sample is examined and classified as good/defective

If the number of defective exceeds a specified rejection number (c) the whole

lot is rejected; otherwise the whole lot is accepted

2.Double Sampling Plan

A Double Sampling Plan allows to take a second sample if the results of the original

sample are inconclusive.

Specifies the lot size, size of the initial sample, the accept/reject/inconclusivecriteria for the initial sample (N, n1, c1 (Ac), r1(Re))

Specifies the size of the second sample and the acceptance rejection criteria based

on the total number of defective observed in both the first and second sample

(n2,c2,r2)

2 Double Sampling Plan


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First Random sampleLot

C1 r1

First sample inconclusive,

take second sampleReject LotAccept Lot

Compare number of defective found in the first random sample to

C1 and r1 and make appropriate decision.


2 D bl S li Pl


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C2

Reject LotAccept Lot

Compare the total number of defective in both lots to C2 and make the

appropriate decision

LotFirst Random sample

Second Random sample


3 M lti l S li Pl


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3.Multiple Sampling Plan

A Multiple Sampling Plan is similar to the double sampling plan in that successive trials

are made, each of which has acceptance, rejection and inconclusive options.

Which Plan you choose depends on:

Cost and time

Number of samples needed and number of items in each sample

Average Outgoing Quality (AOQ)

The average outgoing quality is only

applicable to the characteristics defective

units, defects per unit, and defects per

quantity and assumes rejected lots are100% inspected and all defectives/defects

are removed

In this case, all rejected lots are made

perfect and the only defects left are those

in lots that were accepted.

AOQ and Acceptance Sampling
http://www.variation.com/spa/help/hs300.htmhttp://www.variation.com/spa/help/hs300.htmhttp://www.variation.com/spa/help/hs320.htmhttp://www.variation.com/spa/help/hs340.htmhttp://www.variation.com/spa/help/hs340.htmhttp://www.variation.com/spa/help/hs340.htmhttp://www.variation.com/spa/help/hs340.htmhttp://www.variation.com/spa/help/hs320.htmhttp://www.variation.com/spa/help/hs300.htmhttp://www.variation.com/spa/help/hs300.htm


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AOQ and Acceptance Sampling

ProducerN=3000

n=89

c=2Consumer

15 lots

2% nonconforming

11 lots

2% nonconforming

4 lots2% nonconforming

4 lots

0% nonconforming

How acceptance Sampling works


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unit iv - maintenance, system reliability & tqm

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