Quality Management Lecture 6. Quality of Products and Services
Jan 13, 2016
Quality Management Lecture 6.
Quality of Products and Services
Concept of quality 1 Totality of features and characteristics of a product or
service that bears upon its ability to satisfy stated or implied needs.
These needs can be Objective (determined in contracts, or in standards) – easy to
measure Subjective (usefulness) – it belongs to the custemer
What could be an objective and a subjective measure for the quality of a book? Book jacket Quality of the paper publisher Author contents
Concept of quality 2
Nowadays it has a strategic definition, because it not just mean the quality of a product, but it : „It is a basic business strategy, which means that products and services should totally meet both internal and external customers stated and latent needs.
Quality is defined as meeting customers requirements
5 Approaches to Defining Quality – Garvin 1 The Transcendent Approach: a quality cannot be defined
precisely, we learn to recognize it only through experience Innate excellence Pictures of Picasso:
5 Approaches to Defining Quality - Garvin 2 The Product-based Approach: quality is precise and
measurable variable, products can be ranked – quality products have more attributes (computer with more memory)
5 Approaches to Defining Quality - Garvin 3 The Manufacturing-based Approach : products or services meet
stated requirements, Manufacturing and engineering practise - Quality is measured by
the manufacturer’s ability to target the requirements consistently with little variability
5 Approaches to Defining Quality - Garvin 4 The User-based Approach : quality of a
product is determined by the consumer. There is widely varying individual preferences;
5 Approaches to Defining Quality - Garvin 5 The Value-based
Approach : quality is defined in costs and prices. How much is the benefit of the good or servce outweigh the cost?
Did the costumer get his or her money’s worth?
Quality of Products
Quality of design – determined before the product is produced, to meet costumers’ needs
Quality of conformance – producing a product to meet qualifications.
The abilities: Availability – continuity of a service to the customer Availability=uptime/(uptime+downtime) Reliability – the length of time that a product can be used before
it fails - MTBF Maintainability – restoration of a product to service once it has
failed – MTTRAvailability=MTBF/(MTBF+MTTR)
Field service or customer service – warrenty and repair or replacement of a produt after it has been sold
8 Dimensions of product quality - Garvin Performance – refers to a products’ primary operating
characteristics Features – „bells and whistles” added to a products Reliability – probability that the product will not fail in a specific
period of time (MTPF – mean time between failure) Conformance – the degree to which a product or service meets
its specifications Durability – a measure of the product life Serviceability – this is the speed, the competence and easy of
repair Aesthetics – how the product looks, feels, sounds, tastes and
smells. This is clearly a matter of personal judgment Perceived quality – images, advertising, and brand names can
be critical to give information about the product quality
Quality cycle
Engineering
Defines design concept
Prepares specifications
Defines quality characteristics
Marketing
Interprets Customer needs
Works with Customer to design product to fit operations
Customer
Specifies quality needs
Operations
Produces the product or service
Quality Control
Plans and monitors quality
Quality of Services
HIPI priciples
Heterogenity (variability in the quality of service because services are provided by people, and people perform inconsistently)
Intangibility (there is no specimen ) Perishability (vary in demand can occure
difficulty in supply) Inseparability (good service can’t be
separated from bad service)
SERQUAL - quality dimensions of services Reliability - service is performed with high accuracy and thoroughness
Responsiveness - the willingness of employees to provide the service and how fats the service is provided
Competence - possession of required skills, and knowledge Access - approachability and ease of contact Courtesy -comprises politeness, respect, friendliness Communication - informing the customers in an
understandable way and listening to them Credibility - trustworthiness and honesty Security - physical and financial safety Understanding the customer - steps to know customer better Tangibles - all physical products that are involved in service
delivery
RATER model
Reliability Assurance – Involves knowledge and courtesy of
employees and their ability to inspire trust and confidence
Tangibles – Empathy – Which is caring, individualized or
customized attention the organization provides its customers
ResponsivenessIt is an efficient model in helping an organization shape
up their efforts in bridging the gap between perceived and expected service.
GAP model GAP 1 (Knowledge Gap) – the difference between guest’s
expectation and management perceptions of those expectations, i. e. not knowing what consumer expect
GAP 2 (Standards Gap) – difference between managements perceptions of guest’s expectations and service quality
specifications , i.e. improper service quality standards GAP 3 (Delivery Gap) – difference between service quality
specifications and service actually delivered, i.e. the service performance gap
GAP 4 (Communication Gap) – difference between service delivery and the communications to the guests about service delivery, i.e. whether promised match delivery?
GAP 5 (Overall Gap) – the difference between guests expectation and perceieved service.
Developing of Quality Systems
Quality Check (QCh)
Method: testing product at the end of a process, compare with stated specifications
It regards to products Goals: detecting defections, a separate
refuse Result: prevent refuse from moving to
another step of production
Statistical Qualty Control (SQC) Goals: ensure that mistakes can not arise
again It regards to processes Method: continuous improvement of
processes: PDCA cycle – Plan, Do, Check, Act
Results: prevent mistakes from arising again,
Quality Management System (QMS) Goals: ensure that mistakes can not arise at
all It regards to the whole system: organization,
processes, resources, Method: regular audits, when compare the
whole system with specifications stated in documentations
Results: the product and operation are optimized to the customers’ requirements (the best possible soultion)
Total Quality Management - TQM Management approach for an organization General Principles of TQM:
Customer Focus: both actions and functions are designed and performed with the aim os meeting the needs of customers, this will ensure long-term success
Continouos process improvement Commitment and personnel involvement:
employees assume responsibilities to achive quality accomplishing their task, and actively take part in the process of continuous improvement.
International Standardization Organization - ISO ISO 9000 is a family of standards for quality
management systems. In 1994, 2000 and 2008 the rules are updated, as
the requirements motivate changes over time. It can be audited by internal or external experts.
Under the 1994 version, the question was broadly "Are you doing what the manual says you should be doing?", whereas under the 2000 version, the question is more "Will this process help you achieve your stated objectives? Is it a good process or is there a way to do it better?"
Cost of quality
Control Costs (CC)
related to the activities which remove defects from the production stream. Prevention: include activities such as quality
planning, new-product reviews, training, engineering analysis. These activities prevent defects before they occure.
Appraisal: eliminating deffects after they occure but before the product reach the customer
Failure Costs (FC)
internal faliure cost incurres during the production process. Include rework, quality downgradeing, machine downtime
external failure cost incurres after the product is shipped. Includes warranty charges, returned goods, allowances.
TC=CC+FC=PC+AC+IFC+EFC
Total Cost
Cost of failures
Total cost
Cost of control
Minimum cost
Number of defects produced
cost
Excercise
Cost of failure:
F=1500+40X Cost of control
C=3080/X
X-percent defective
What is the minimum cost of quality, and the optimal percent deffective?
Solution
TC=FC+CC= 1500+40X+3080/X TC/dX=40-3080/X2=0 40X2=3080 X2=77 X=8,77 TCmin=2202
F(x)=xn
F(x)/dx=n*x(n-1)
Seminar - Excercise
Scaling Procedure Based on the Method of Paired Comparsion Attributes of products are not equally
important for customers We have to discover the rank of these
features and thus we can focuse on the main needs of customers.
Exercise
Coffee: Hot (I1) Milky (I2) Sweet (I3) Strenght (I4)
Create pairs (1-2; 4-1; 3-2; 1-3;2-4; 3-4;) Rank them randomly or use Ross-method Compare them, underline the preferred item
Create Preference Matrix – this contains preferences. Both in the rows and in the cols the dimensons are presented. When someone prefer item in row to item in col there is 1, otherwise 0.
In the last col there is the sum of the value being in the row. This means how often the row item was preferred to the others.
I1 I2 I3 I4 a
I1 - 0 1 1 2
I2 1 - 0 1 2
I3 0 1 - 0 1
I4 0 0 1 - 1
Consistency test There are 3 item: A, B, C If A>B and B>C then A>C When decision maker is not consistent then this
statement is not true. Consistency coeeficient:
Where dmax is the maximum number of incosistent decisions
If n is odd number
If n is even number:
%100*)1(maxd
dK
24
43
max
nnd
24
)( 3
max
nnd
212
)12)(1( 2annnd
Example
dmax=(27-3)/24=1 d=4(4-1)(8-1)/12-
(4+4+4)/2=7-6=1 K=1-1/1=0% This is an inconsistent
decision maker. The decision maker
consistent when K>85%
I1 I2 I3 I4 a
I1 - 0 1 1 2
I2 1 - 0 1 2
I3 0 1 - 1 2
I4 0 0 0 - 0
Creation of weighted number
Preference fraction:
Where „m” is the number of decision makers.
To get the weighted number we have to transform Pa value into a normal distribution or simply calculate the percentage value of it.
if m=14
nm
ma
Pa *2
%100*minmax
min
aa
aai
PP
PP
Totalized preference matrix I1 I2 I3 I4 I5 I6 I7 I8 I9 I10 a a+m/2 Pa
I1 2 13 7 7 2 0 1 7 6 45 52 0,37
I2 12 9 8 10 10 0 1 6 6 62 69 0,49
I3 1 5 0 0 2 1 0 1 0 10 17 0,12
I4 7 6 14 8 11 2 1 2 5 56 63 0,45
I5 7 4 14 6 5 0 1 0 1 38 45 0,32
I6 12 4 12 3 9 0 0 0 4 44 51 0,36
I7 14 14 13 12 14 14 13 14 14 122 129 0,92
I8 13 13 14 13 13 14 1 12 13 106 113 0,92
I9 7 8 13 12 14 14 0 2 1 71 78 0,55
I10 8 8 14 9 13 10 0 1 13 76 83 0,59
Rj 81 64 116 70 88 82 4 20 55 50 630
18 1 53 7 25 19 -59 -43 -8 -13
324 1 2809 49 625 361 3481 1849 64 169 9732
jj RR 2)( jj RR
Kedall coefficient of concordance (W) Rj is the sum of the
colums in the totalized preference matrix
is the mean of Rj-s
Δ is the squared distance
m is the number of decision maker
n is the number of items
12
)( 32
max
nnm
j
jj RR 2)(
2
)1(
nmR j
max
W
jR
Meaning of the Kendall Coefficient Kendall's coefficient of concordance is used
traditionally in statistics for measuring agreement between k orderings.
If it is 1 there is total concordance. If it is 0 there is no concordance at all. But it
even occure in that case when there is two group of decision maker with opposite oppinion. Then cluster analyize should be used to discover the groups.
Thank You for Attention