1 Measurement and Units Seven Fundamental SI Units of Measurement.
Units of Measurement - bkngpnarnaul.ac.in
Transcript of Units of Measurement - bkngpnarnaul.ac.in
Units of Measurement A unit of measurement is a definite magnitude of a quantity, defined and adopted by convention or by law, that is used as a standard for measurement of the same kind of quantity. Any other quantity of that kind can be expressed as a multiple of the unit of measurement. For example, a length is a physical quantity. The metre is a unit of length that represents a definite predetermined length. When we say 10 metres (or 10 m), we actually mean 10 times the definite predetermined length called "metre". Measurement is a process of determining how large or small a physical quantity is as compared to a basic reference quantity of the same kind.
Standards for Measurement In metrology (the science of measurement),
a standard (or etalon) is an object, system, or experiment that bears a defined relationship to a unit of measurement of a physical quantity.[1] Standards are the fundamental reference for a system of weights and measures, against which all other measuring devices are compared. Historical standards for length, volume, and mass were defined by many different authorities, which resulted in confusion and inaccuracy of measurements. Modern measurements are defined in relationship to internationally standardized reference objects, which are used under carefully controlled laboratory conditions to define the units of length, mass, electrical potential, and other physical quantities.
Types of standards
Primary standard • A set of gauge blocks are used as a working standard to check the calibration of
measurement tools such as micrometers. • An example of a primary standard is the international prototype kilogram (IPK) which is the
master kilogram and the primary mass standard for the International System of Units (SI). The IPK is a one kilogram mass of a platinum-iridium alloy maintained by the International Bureau of Weights and Measures (BIPM) in Sèvres, France.
• Secondary reference standards • Secondary reference standards are very close approximations of primary reference
standards. For example, major national measuring laboratories such as the US's National Institute of Standards and Technology (NIST) will hold several "national standard" kilograms, which are periodically calibrated against the IPK and each other.
• Working standards • Although the SI definition of the "meter" is based on a laboratory procedure combining the
speed of light and the duration of a second, a machine shop will have a physical working standard (gauge blocks for example) that are used for checking its measuring instruments. Working standards and certified reference materials used in commerce and industry have a traceable relationship to the secondary and primary standards.
• Working standards are expected to deteriorate, and are no longer considered traceable to a national standard after a time period or use count expires.
• Laboratory standards • National organizations provide calibration and private industrial laboratories with items,
processes and/or certification so they can provide certified traceability to national standards. (In the United States, NIST operates the NVLAP program. These laboratory standards are kept in controlled conditions to maintain their precision, and used as a reference for calibration and creating working standards. Sometimes they are (incorrectly) called "secondary standards" because of their high quality and reference suitability.
Interchangeability
• Interchangeable manufacture means that any part or component picked at random from a manufactured lot should fit and function properly with any other part with which it is required to be fitted, picked at random from a lot manufactured at a different time or place even by a different worker on a different machine.
• The concept of interchangeability requires that each part or assembly going into a final product must be made to definite size, shape and finish specifications.
• The interchangeable manufacturing system is responsible to a great extent for the high standard of living enjoyed by mankind today.
• The advantages of interchangeable manufacturing include the following: • It makes possible the standardization of products and methods of
manufacturing. • It provides for ease of assembly and maintenance of products. • It allows mass production of products thus making it possible to take
advantage of economics of scale in terms of manufacturing costs and cost of raw materials etc.
• Because of larger volume of production, specialized processes and machines can be employed thus reducing manufacturing time and cost per piece.
International standard
• International standards are standards developed by international standards organizations. International standards are available for consideration and use worldwide. The most prominent organization is the International Organization for Standardization (ISO).
• International standards may be used either by direct application or by a process of modifying an international standard to suit local conditions. The adoption of international standards results in the creation of equivalent, national standards that are substantially the same as international standards in technical content, but may have (i) editorial differences as to appearance, use of symbols and measurement units, substitution of a point for a comma as the decimal marker, and (ii) differences resulting from conflicts in governmental regulations or industry-specific requirements caused by fundamental climatic, geographical, technological, or infrastructural factors, or the stringency of safety requirements that a given standard authority considers appropriate.
Planning of inspection • A document that provides instructions on how an
inspection of a product is to take place. Inspection plans provide details about what characteristics must be tested in order to ensure the quality of the product, as well as specific metrics and measurements that must be achieved in order for the product to be judged in compliance with standards.
• What is an inspection plan: a. check machine tool for accuracy b. select the critical and important dimensions to inspect c. select the measuring insturments d. construct SPC charts for all dimensions
Measurement Procedure in which an unknown quantity is
compared to a known standard, using an accepted and consistent system of units
• The measurement may involve a simple linear rule to scale the length of a part
• Or it may require a sophisticated measurement of force versus deflection during a tension test
• Measurement provides a numerical value of the quantity of interest, within certain limits of accuracy and precision
Rulers and Feeler Gauges
• Rulers
– Simple tools to measure straight-line distances where tolerances are not a major factor
– May be USC or metric
– Can be made of metal, plastic, or wood
– Typical rulers are 6 inches or 12 inches
Rulers and Tapes
Rulers and tapes. The most common method of obtaining simple measurements of length is by the ruler or tape .A ruler may be graduated into feet, inches, or fractions thereof. Rulers and tapes used in engineering work are most frequently made of metal and the fractions of inches may be graduated to subdivisions as small as 1/64 or 1/100 of an inch. Care should be exercised in using metal rulers and tapes, especially if extreme accuracy is required. The margin of error due to expansion or contraction of the instrument from changes in temperature can be considerable.
Calipers
• Calipers. Engineers and machinists frequently use calipers to secure accurate measurements of inside and outside diameters.
Feeler Gauges
• Feeler Gauges
– Precision-machined piece of metal that is flat or round
– May be USC or metric
– Used for measuring “gaps” or the space between two objects
– Proper usage requires practice
Feeler Gauges used for
• Valve lash
• Measure spark plug gap
• Head flatness
• Thrust distance in Crankshaft
• Ignition point gap (Old Vehicles)
Feeler gages are principally used in determining clearances between various parts of machinery. Probably the most common use is determining valve clearance. Various blades are inserted between the tappet and the push rod until a blade of the feeler gage is found that will just slide between the two surfaces without too much friction or sticking. The thickness of the blade then determines the clearance. Or, a particular feeler of proper thickness may be selected and the tappet adjusted until the feeler will just slide between the tappet and push rod with out
catching.
Feeler Gauges
Such a gage consists of thin blades of metal of various thicknesses. There is generally a blade or strip for each of the most commonly used thicknesses such as 0.002 inch, 0.010 inch, and .015 inch. The thickness of each blade is generally etched on the blade
Micrometer ID
Micrometers
• Micrometer calipers. Engineers frequently rely on the micrometer caliper to obtain measurements accurate to 1/1000 of an inch. This instrument is particularly useful for measuring relatively short lengths and the diameter of journals or cylinders. The common commercial micrometer consists of a frame; an anvil, or fixed measuring point; a spindle; a sleeve, or barrel; and a thimble. The spindle has threads cut 40 to the inch on the portion that fits inside the sleeve. The thimble fits over the end of the sleeve, and rotating the thimble turns the spindle.
Micrometers
• Micrometers precisely measure different shapes of a component
• Outside micrometers
– Resembles a clamp to measure linear distances
– Proper use requires practice and studying the markings of the instrument
Reading a Micrometer
• Sleeve: The Micrometer sleeve is divided into 10
equal parts, each of these parts is equal to
.100" (1 tenth of an inch). Each of these 10
parts is divided into 4 equal parts. Each of these
4 subdivisions is equal to .025" or one 40th of an
inch. More simply, the line on the sleeve marked
"1" represents .100", the line marked "2"
represents .200" and so forth.
• The Sleeve does not move. It looks like a ruler with ten numbers. The space between each number is divided into quarters. As the Thimble rotates around this Sleeve it covers up, or reveals the numbers marked on the Sleeve.
Thimble The thimble is divided into twenty-five
equal parts, each of these parts is equal
to .001" and, one complete rotation of
the thimble coincides with the smallest
division (.025") on the sleeve.
It is easy to read a micrometer if you think of the markings on the Sleeve as
dollars and quarters
Micrometers
• Micrometer Calibration
– In order to measure accurately, the micrometer must be accurate itself
– Extreme temperatures can affect accuracy
Micrometers
• Reading a USC Outside Micrometer
– Place anvil against work
– Rotate thimble to bring spindle into contact with opposite side of work
– Use ratchet knob to ensure sufficient contact is made
– Remove micrometer and read dial
Statistical Quality Control
Learning Objectives
• Describe categories of SQC
• Explain the use of descriptive statistics in measuring quality characteristics
• Identify and describe causes of variation
• Describe the use of control charts
• Identify the differences between x-bar, R-, p-, and c-charts
Learning Objectives –con’t
• Explain process capability and process capability index
• Explain the concept six-sigma
• Explain the process of acceptance sampling and describe the use of OC curves
• Describe the challenges inherent in measuring quality in service organizations
Three SQC Categories
Statistical quality control (SQC): the term used to describe the set of
statistical tools used by quality professionals; SQC encompasses
three broad categories of:
1. Statistical process control (SPC)
2. Descriptive statistics include the mean, standard deviation, and
range
Involve inspecting the output from a process
Quality characteristics are measured and charted
Helps identify in-process variations
3. Acceptance sampling used to randomly inspect a batch of goods to
determine acceptance/rejection
Does not help to catch in-process problems
Sources of Variation
• Variation exists in all processes.
• Variation can be categorized as either:
– Common or Random causes of variation, or
• Random causes that we cannot identify
• Unavoidable, e.g. slight differences in process variables like
diameter, weight, service time, temperature
– Assignable causes of variation
• Causes can be identified and eliminated: poor employee training,
worn tool, machine needing repair
Descriptive Statistics
• Descriptive Statistics include:
– The Mean- measure of central tendency
– The Range- difference between largest/smallest observations in a set of data
– Standard Deviation measures the amount of data dispersion around mean
– Distribution of Data shape • Normal or bell shaped or • Skewed
n
x
x
n
1i
i
1n
Xx
σ
n
1i
2
i
Distribution of Data
• Normal distributions
• Skewed distribution
SPC Methods-Developing Control Charts
Control Charts (aka process or QC charts) show sample data plotted on a graph with CL, UCL, and LCL
Control chart for variables are used to monitor characteristics that can be measured, e.g. length, weight, diameter, time
Control charts for attributes are used to monitor characteristics that have discrete values and can be counted, e.g. % defective, # of flaws in a shirt, etc.
Setting Control Limits
• Percentage of values under normal curve
• Control limits balance
risks like Type I error
Control Charts for Variables
• Use x-bar and R-bar charts together
• Used to monitor different variables
• X-bar & R-bar Charts reveal different problems
• Is statistical control on one chart, out of control on the other chart? OK?
Control Charts for Variables
• Use x-bar charts to monitor the changes in the mean of a process (central tendencies)
• Use R-bar charts to monitor the dispersion or variability of the process
• System can show acceptable central tendencies but unacceptable variability or
• System can show acceptable variability but unacceptable central tendencies
xx
xx
n21
zσxLCL
zσxUCL
sample each w/in nsobservatio of# the is
(n) and means sample of # the is )( where
n
σσ ,
...xxxx x
kk
Constructing an X-bar Chart: A quality control inspector at the Cocoa Fizz soft drink company has taken three samples with four observations each of the volume of bottles filled. If the standard
deviation of the bottling operation is .2 ounces, use the below data to develop control charts with limits of 3 standard deviations for the 16 oz. bottling operation.
Center line and control limit formulas Time 1 Time 2 Time 3
Observation 1 15.8 16.1 16.0
Observation 2 16.0 16.0 15.9
Observation 3 15.8 15.8 15.9
Observation 4 15.9 15.9 15.8
Sample means (X-bar)
15.875 15.975 15.9
Sample ranges (R)
0.2 0.3 0.2
Solution and Control Chart (x-bar)
• Center line (x-double bar):
• Control limits for±3σ limits:
15.923
15.915.97515.875x
15.624
.2315.92zσxLCL
16.224
.2315.92zσxUCL
xx
xx
X-Bar Control Chart
Control Chart for Range (R)
• Center Line and Control Limit formulas:
• Factors for three sigma control limits
0.00.0(.233)RDLCL
.532.28(.233)RDUCL
.2333
0.20.30.2R
3
4
R
R
Factor for x-Chart
A2 D3 D4
2 1.88 0.00 3.27
3 1.02 0.00 2.57
4 0.73 0.00 2.28
5 0.58 0.00 2.11
6 0.48 0.00 2.00
7 0.42 0.08 1.92
8 0.37 0.14 1.86
9 0.34 0.18 1.82
10 0.31 0.22 1.78
11 0.29 0.26 1.74
12 0.27 0.28 1.72
13 0.25 0.31 1.69
14 0.24 0.33 1.67
15 0.22 0.35 1.65
Factors for R-Chart Sample Size
(n)
R-Bar Control Chart
Second Method for the X-bar Chart Using
R-bar and the A2 Factor
• Use this method when sigma for the process distribution is not know
• Control limits solution:
15.75.2330.7315.92RAxLCL
16.09.2330.7315.92RAxUCL
.2333
0.20.30.2R
2x
2x
Control Charts for Attributes –P-Charts & C-Charts
Attributes are discrete events: yes/no or pass/fail – Use P-Charts for quality characteristics that are discrete and involve
yes/no or good/bad decisions • Number of leaking caulking tubes in a box of 48
• Number of broken eggs in a carton
– Use C-Charts for discrete defects when there can be more than one defect per unit • Number of flaws or stains in a carpet sample cut from a production run
• Number of complaints per customer at a hotel
P-Chart Example: A production manager for a tire company has inspected the number of defective tires in five random samples with 20 tires in each
sample. The table below shows the number of defective tires in each sample of 20 tires. Calculate the control limits.
Sample Number of
Defective Tires
Number of Tires in each
Sample
Proportion Defective
1 3 20 .15
2 2 20 .10
3 1 20 .05
4 2 20 .10
5 2 20 .05
Total 9 100 .09
Solution:
0.1023(.064).09σzpLCL
.2823(.064).09σzpUCL
0.6420
(.09)(.91)
n
)p(1pσ
.09100
9
Inspected Total
Defectives#pCL
p
p
p
P- Control Chart
C-Chart Example: The number of weekly customer complaints are monitored in a large hotel using a
c-chart. Develop three sigma control limits using the data table below.
Week Number of Complaints
1 3
2 2
3 3
4 1
5 3
6 3
7 2
8 1
9 3
10 1
Total 22
Solution:
02.252.232.2ccLCL
6.652.232.2ccUCL
2.210
22
samples of #
complaints#CL
c
c
z
z
C- Control Chart
Process Capability
Product Specifications
– Preset product or service dimensions, tolerances: bottle fill might be 16 oz. ±.2 oz.
(15.8oz.-16.2oz.)
– Based on how product is to be used or what the customer expects
Process Capability – Cp and Cpk
– Assessing capability involves evaluating process variability relative to preset product
or service specifications
– Cp assumes that the process is centered in the specification range
– Cpk helps to address a possible lack of centering of the process
6σ
LSLUSL
width process
width ionspecificatCp
3σ
LSLμ,
3σ
μUSLminCpk
Relationship between Process Variability and Specification Width
• Three possible ranges for Cp
– Cp = 1, as in Fig. (a), process variability just meets specifications – Cp ≤ 1, as in Fig. (b), process not capable
of producing within specifications
– Cp ≥ 1, as in Fig. (c), process exceeds minimal specifications
• One shortcoming, Cp assumes that the process is centered on the specification range
• Cp=Cpk when process is centered
Computing the Cp Value at Cocoa Fizz: 3 bottling machines are being evaluated for possible use at the Fizz plant. The machines must be capable of meeting the design specification of 15.8-16.2 oz. with at least a process capability index of 1.0 (Cp≥1)
The table below shows the information gathered from production runs on each machine. Are they all acceptable?
Solution: – Machine A
– Machine B
Cp=
– Machine C
Cp=
Machine σ USL-LSL 6σ
A .05 .4 .3
B .1 .4 .6
C .2 .4 1.2
1.336(.05)
.4
6σ
LSLUSLCp
Computing the Cpk Value at Cocoa Fizz
• Design specifications call for a target value of 16.0 ±0.2 OZ.
(USL = 16.2 & LSL = 15.8)
• Observed process output has now shifted and has a µ of 15.9 and a
σ of 0.1 oz.
• Cpk is less than 1, revealing that the process is not capable
.33.3
.1Cpk
3(.1)
15.815.9,
3(.1)
15.916.2minCpk
±6 Sigma versus ± 3 Sigma
• In 1980’s, Motorola coined “six-sigma” to describe their higher quality efforts
Six-sigma quality standard is now a benchmark in many industries – Before design, marketing ensures
customer product characteristics
– Operations ensures that product design characteristics can be met by controlling materials and processes to 6σ levels
– Other functions like finance and accounting use 6σ concepts to control all of their processes
• PPM Defective for ±3σ versus ±6σ quality
Acceptance Sampling
Defined: the third branch of SQC refers to the process of randomly inspecting a certain number of items from a lot or batch in order to decide whether to accept or reject the entire batch
• Different from SPC because acceptance sampling is performed either before or after the process rather than during
– Sampling before typically is done to supplier material
– Sampling after involves sampling finished items before shipment or finished components prior to assembly
• Used where inspection is expensive, volume is high, or inspection is destructive
Acceptance Sampling Plans
Goal of Acceptance Sampling plans is to determine the criteria for acceptance or
rejection based on:
– Size of the lot (N)
– Size of the sample (n)
– Number of defects above which a lot will be rejected (c)
– Level of confidence we wish to attain
• There are single, double, and multiple sampling plans
– Which one to use is based on cost involved, time consumed, and cost of passing on a
defective item
• Can be used on either variable or attribute measures, but more commonly used
for attributes
Operating Characteristics (OC) Curves
• OC curves are graphs which show the probability of accepting a lot given various proportions of defects in the lot
• X-axis shows % of items that are defective in a lot- “lot quality”
• Y-axis shows the probability or chance of accepting a lot
• As proportion of defects increases, the chance of accepting lot decreases
• Example: 90% chance of accepting a lot with 5% defectives; 10% chance of accepting a lot with 24% defectives
AQL, LTPD, Consumer’s Risk (α) & Producer’s Risk (β)
• AQL is the small % of defects that consumers are willing to accept; order of 1-2%
• LTPD is the upper limit of the percentage of defective items consumers are willing to tolerate
• Consumer’s Risk (α) is the chance of accepting a lot that contains a greater number of defects than the LTPD limit; Type II error
• Producer’s risk (β) is the chance a lot containing an acceptable quality level will be rejected; Type I error
Developing OC Curves
• OC curves graphically depict the discriminating power of a sampling plan
• Cumulative binomial tables like partial table below are used to obtain probabilities of accepting a lot given varying levels of lot defectives
• Top of the table shows value of p (proportion of defective items in lot), Left hand column shows values of n (sample size) and x represents the cumulative number of defects found
Table 6-2 Partial Cumulative Binomial Probability Table (see Appendix C for complete table)
Proportion of Items Defective (p)
.05 .10 .15 .20 .25 .30 .35 .40 .45 .50
n x
5 0 .7738 .5905 .4437 .3277 .2373 .1681 .1160 .0778 .0503 .0313
Pac 1 .9974 .9185 .8352 .7373 .6328 .5282 .4284 .3370 .2562 .1875
AOQ .0499 .0919 .1253 .1475 .1582 .1585 .1499 .1348 .1153 .0938
Example: Constructing an OC Curve
• Lets develop an OC curve for a sampling plan in which a sample of 5 items is drawn from lots of N=1000 items
• The accept /reject criteria are set up in such a way that we accept a lot if no more that one defect (c=1) is found
• Using Table 6-2 and the row corresponding to n=5 and x=1
• Note that we have a 99.74% chance of accepting a lot with 5% defects and a 73.73% chance with 20% defects
Average Outgoing Quality (AOQ)
• With OC curves, the higher the quality of the lot, the higher is the chance that it will be accepted
• Conversely, the lower the quality of the lot, the greater is the chance that it will be rejected
• The average outgoing quality level of the product (AOQ) can be computed as follows: AOQ=(Pac)p
• Returning to the bottom line in Table 6-2, AOQ can be calculated for each proportion of defects in a lot by using the above equation
• This graph is for n=5 and x=1 (same as c=1)
• AOQ is highest for lots close to 30% defects
Implications for Managers
• How much and how often to inspect? – Consider product cost and product volume
– Consider process stability
– Consider lot size
• Where to inspect? – Inbound materials
– Finished products
– Prior to costly processing
• Which tools to use? – Control charts are best used for in-process production
– Acceptance sampling is best used for inbound/outbound
SQC in Services
• Service Organizations have lagged behind manufacturers in the use of statistical quality control
• Statistical measurements are required and it is more difficult to measure the quality of a service
– Services produce more intangible products
– Perceptions of quality are highly subjective
• A way to deal with service quality is to devise quantifiable measurements of the service element
– Check-in time at a hotel
– Number of complaints received per month at a restaurant
– Number of telephone rings before a call is answered
– Acceptable control limits can be developed and charted
Service at a bank: The Dollars Bank competes on customer service and is concerned about service time at their drive-by windows. They recently installed new system software which they hope will meet service specification limits of 5±2 minutes and have a Capability Index
(Cpk) of at least 1.2. They want to also design a control chart for bank teller use.
They have done some sampling recently (sample size: 4 customers) and determined that the process mean has shifted to 5.2 with a Sigma of 1.0 minutes.
Control Chart limits for ±3 sigma limits
1.21.5
1.8Cpk
3(1/2)
5.27.0,
3(1/2)
3.05.2minCpk
1.33
4
1.06
3-7
6σ
LSLUSLCp
minutes 6.51.55.04
135.0zσXUCL xx
minutes 3.51.55.04
135.0zσXLCL xx
SQC Across the Organization
SQC requires input from other organizational functions, influences their success, and used in designing and evaluating their tasks – Marketing – provides information on current and future
quality standards – Finance – responsible for placing financial values on SQC
efforts – Human resources – the role of workers change with SQC
implementation. Requires workers with right skills – Information systems – makes SQC information accessible for
all.
INTRODUCTION TO TQM
What is TQM?
TQM is the integration of all functions and processes within an
organization in order to achieve continuous improvement of
the quality of goods and services. The goal is customer
satisfaction.
“ No doubt , humans are always deficient”
(Al-Quran)
The Three Quality Gurus
• Deming: the best known of the “early” pioneers, is
credited with popularizing quality control in Japan in early
1950s.Today, he is regarded as a national hero in that
country and is the father of the world famous Deming prize
for quality.
JURAN
• Juran, like Deming was invited to Japan in 1954 by the union of Japanese Scientists and engineers.
• Juran defines quality as fitness for use in terms of design, conformance, availability, safety and field use. He focuses on top-down management and technical methods rather than worker pride and satisfaction.
Philip Crosby: author of popular book Quality is
Free. His absolutes of quality are:
• Quality is defined as conformance to requirements, not
“goodness”
• The system for achieving quality is prevention, not
appraisal.
• The performance standard is zero defects, not “that’s close
enough”
• The measurement of quality is the price of non-
conformance, not indexes.
Commonality of Themes of Quality Gurus
• Inspection is never the answer to quality improvement, nor is “policing”.
• Involvement of leadership and top management is essential to the necessary culture of commitment to quality.
• A program for quality requires organization-wide efforts and long term commitment, accompanied by the necessary investment in training.
• Quality is first and schedules are second.
DIFINITION OF QUALITY
• The concept and vocabulary of quality are elusive. Different people interpret quality differently. Few can define quality in measurable terms that can be proved operationalized. When asked what differentiates their product or service;
The banker will answer” service”
The healthcare worker will answer “quality health care”
The hotel employee will answer “customer satisfaction”
The manufacturer will simply answer “quality product”
Five Approaches of Defining Quality
• Harvard professor David Garvin, in his book Managing Quality summarized five principal approaches to define quality.
• Transcendent
• Product based
• User based
• Manufacturing based
• Value based
Transcendental view
• Those who hold the transcendental view would say “I can’t define it, but I know it when I see it”
• Advertisers are fond of promoting products in these terms.
“ Where shopping is a pleasure” (supermarket). “We love to fly and it shows" (airline).
Television and print media are awash with such indefinable claims and therein lies the problem:
• Quality is difficult to define or to operationalize. It thus becomes elusive when using the approach as basis for competitive advantage. Moreover, the functions of design, production and service may find it difficult to use the definition as a basis for quality management.
PRODUCT BASED
• Quality is viewed as a quantifiable or measurable
characteristic or attribute. For example durability or
reliability can be measured and the engineer can design to
that benchmark.
• Quality is determined objectively.
• Although this approach has many benefits, it has limitation
as well. Where quality is based on individual taste or
preference, the benchmark for measurement may be
misleading.
USER BASED
It is based on idea that quality is an individual matter and products that best satisfy their preferences are those with the highest quality. This is rational approach but leads to two problems;
Consumer preference vary widely and it is difficult to aggregate these preferences into products with wide appeal. This leads to the choice between a niche strategy or a market aggregation approach which tries to identify those product attributes that meet the needs of the largest number of consumers.
Another problem concerns the answer to the question “Are quality and customer satisfaction the same?” the answer is probably not. One may admit that a Lincoln continental has many quality attribute, but satisfaction may be better achieved with an Escort.
MANUFACTURING BASED
• Manufacturing-based definitions are concerned primarily with engineering and manufacturing practices and use the universal definition of “conformance to requirements”. Requirements or specifications are established by design and any deviation implies a reduction in quality. The concept applies to services as well as product. Excellence in quality is not necessarily in the eye of the beholder but rather in the standards set by the organization.
• This approach has the serious weakness. The consumer’s perception of quality is equated with conformance and hence is internally focused.
Value Based
• It is defined in term of costs and prices as well as number of other attributes. Thus, the consumer’s purchased decision is based on quality at an acceptable price. This approach is reflected in the popular Consumer Reports magazine which ranks products and services based on two criteria: Quality and Value.
• The highest quality is not usually the best value. That designation is assigned to the “best- buy” product or service.
MANAGEMENT OF PROCESS QUALITY
HUMAN RESOURCE DEVELOPMENT AND
MANAGEMENT
STRATEGIC QUALITY
PLANNING
INFORMATION AND ANALYSIS
CUSTOMER FOCUS AND
SATISFACTION
QUALITY AND
OPERATIONAL RESULTS
SENIOR EXECUTIVE
LEADERSHIP
System Approach for TQM
Driver
System
TOW
Triangle of wisdom
LM
DM KM
Characteristics of TQM Leader
• Visible, Committed and Knowledgeable
• A Missionary Zeal
• Aggressive Targets
• Strong Drivers
• Communication of Values
• Organization
• Customers Contact
TQO HRM
Five Principles are:
• Quality Work the First Time
• Focus on the Customer
• Strategic Holistic Approach to Improvement
• CI as a Way of Life
• Mutual Respect and Teamwork
Customer Satisfaction
Three Part System
Customer Expectations
Company Operations
(Processes)
Customer Satisfaction
Indicators for Customer Satisfaction
• Frontline empowerment
• Excellent hiring, training, attitude and morale for front line employees
• Proactive customer service system
• Proactive management of relationship with customers
• Use of all listening posts
• Quality requirements of market segment
• Commitment to customers
• Understanding customer requirements
• Service standards meeting customers requirements
Cost of Quality
Three Views of quality Costs
Higher quality means higher cost.
• Quality attributes such as performance and features cost more in terms of labor, material, design and other costly resources.
• The additional benefits from improved quality do not compensate for additional expense.
The cost of improving quality is less than the resulting savings.
• The saving result from less rework, scrap and other direct expenses related defects.
• This is said to account for the focus on continuous improvement of processes in Japanese firms.
Three Views of quality Costs
Quality costs are those incurred in excess of those that would have been incurred if the product were built or the service performed exactly right the first time.
This view is held by adherents of TQM philosophy.
Costs include not only those that are direct, but also those resulting from lost customers, lost market share and the many hidden costs and foregone opportunities not identified by modern cost accounting systems.
Quality Costs
COST OF QUALITY IS THE COST OF
NON QUALITY
1: 10:100 Rule
“A stitch in time saves nine”
Types of Quality Costs
The cost of quality is generally classified into four categories
1. Cost of Prevention
2. Cost of Appraisal
3. Cost of Internal Failure
4. Cost of External Failure
Quality Costs
Cost of Prevention
• Prevention costs include those activities which remove and prevent defects from occurring in the production process.
• Included are such activities as quality planning, production reviews, training, and engineering analysis, which are incurred to ensure that poor quality is not produced.
Appraisal
• Those costs incurred to identify poor quality products after they occur but before shipment to customers. e.g. Inspection activity.
Quality Costs
Internal Failure
• Those incurred during the production process.
• Include such items as machine downtime, poor quality materials, scrap, and rework.
External Failure
• Those incurred after the product is shipped.
• External failure costs include returns and allowances, warranty costs, and hidden costs of customer dissatisfaction and lost market share.
Benefits of TQM
• Greater customer loyalty
• Market share improvement
• Higher stock prices
• Reduced service calls
• Higher prices
• Greater productivity
ISO 9000
ISO 9000
What You Need To Know
ISO 9000
What are ISO 9000 Standards?
• ISO 9000 Standards
– Define the required elements of an effective quality management system
– Can be applied to any company
– Adopted by the United States as the ANSI/ASQC Q90 series.
• Revised 2000 – wider applicability
ISO 9000
Who created the standards?
• International Organization for Standardization - Geneva
• ISO tech committee - TC 176 started in 1979
• Standards created in 1987
– To eliminate country to country differences
– To eliminate terminology confusion
– To increase quality awareness
ISO 9000
How did ISO get started?
• 1906 - International Electro-technical Commission
• 1926 - International Federation of the National Standardizing Associations (ISA)
• 1946 London - delegates from 25 countries decided to create a new international organization "the object of which would be to facilitate the international coordination and unification of industrial standards
• 1947 - ISO began to officially function
• 1951 - The first ISO standard was published – "Standard reference temperature for industrial length
measurement".
ISO 9000
ISO Organization
General Assembly
Council Technical Management Board
Technical Advisory Groups
Technical Committees
Policy Development Committees
Technical Committees Technical Committees Technical Committees
ISO 9000
What has ISO Accomplished?
• ISO film speed code
• Standard format for telephone and banking cards
• ISO 9000 which provides a framework for quality management and quality assurance
• ISO 14000 series provides a similar framework for environmental management
• Internationally standardized freight containers
• Standardized paper sizes.
• Automobile control symbols
• ISO international codes for country names, currencies and languages
ISO 9000
ISO 9000:2000 Consists of 3 Areas
• ISO 9000:2000 Quality Management Systems: fundamentals and vocabulary
• ISO 9001:2000 Quality Management Systems – Requirements (required for certification) Management responsibility Resource management Product/service realization Measurement, analysis, improvement
• ISO 9004-2000 Quality Management Systems –Guidelines for performance improvement
ISO 9000
ISO 9000 Family of Standards
• ISO 8402 - QA and Quality management vocabulary • ISO 9000-2 - Generic guidelines for applying ISO 9001,
ISO 9002, and ISO 9003 • ISO 9000-3 - Guidelines for applying ISO 9001 to the
development, supply, and maintenance of software
• ISO 9000-4 Application for dependability management • ISO 9004-2 Guidelines for services • ISO 9004-3 Guidelines for processed material • ISO 9004-4 Guidelines for quality improvement • ISO 9004-5 Guidelines for quality plans • ISO 9004-6 Guidelines for configuration management
ISO 9000
What are the elements of the standards?
• Management responsibility • Resource management • Quality System • Contract Review • Design Control • Document Control • Purchasing • Purchaser-Supplied Product • Product Identification and
Traceability • Process Control
• Inspection and Testing • Inspection, Measuring and
Test Equipment • Inspection and Test Status • Control of Non-conforming
product • Corrective Action • Quality Records • Internal Quality Audit • Training • Servicing • Statistical Techniques
ISO 9000
Element Standard: Management Responsibility
• Management must have a written policy statement of their commitment to quality. This policy must be communicated to and understood by all employees.
• Management must clearly define quality-related organizational responsibilities and interrelationships.
• A management representative must be assigned to oversee the implementation and continuous improvement of the quality system.
• Senior management must continually review the system.
ISO 9000
Element Standard: Process Control
• The company must identify all processes that directly affect the quality of the product or service and ensure that these processes are carried out under controlled conditions, including: – Formal approval of process design and equipment. – Documented work instructions. – Development of quality plans describing how the
process is to be monitored. – A suitable working environment. – Documented quality criteria.
ISO 9000
Why is ISO 9000 important?
• European Union directive
– ISO 9000 certification required by suppliers of “Regulated Products”
• health, safety, and the environment
– EC has strict corporate liability legislation protecting consumers
• Globalization impact
ISO 9000
Why adopt ISO 9000?
• To comply with customers who require ISO 9000
• To sell in the European Union market
• To compete in domestic markets
• To improve the quality system
• To minimize repetitive auditing by similar and different customers
• To improve subcontractors’ performance
ISO 9000
Third party registration
Accreditors (RAB in US)
Registrars
Supplier Companies
ASQC
ISO 9000
Ten Steps to ISO Registration
2. Select the appropriate standard
1. Set the registration objective
3. Develop and implement the quality system
4. Select a third-party registrar and apply
5. Perform self-analysis audit
6. Submit quality manual for approval
7. Pre-assessment by registrar
8. Take corrective actions
9. Final assessment by registrar
10. Registration!
ISO 9000
Six Essential Elements of a Successful Registration Effort
Senior Management Commitment to the Effort
Appropriate ISO 9000 Training
An Effective Management Review Process
Documentation of the Quality System
An Effective Internal Auditing System
An Effective Corrective Action Process