Download - MBA 8452 Systems and Operations Management
MBA 8452 Systems and Operations ManagementMBA 8452 Systems and Operations Management
Product Design Product Design & Process & Process Selection Selection ——ServiceService
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QualityManagement
StatisticalProcess Control
Inventory Control
Just in Time
Introduction to Operations Management/ Operations Strategy
ProjectManagement
Planning for ProductionProcess Analysisand Design
Process Controland Improvement
Waiting Line Analysis
Services
Manufacturing
Process Analysis
Job DesignAggregate Planning
Capacity Management
Supply ChainManagement
Layout/ Assembly Line Balancing
Scheduling
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Objectives: Services Design
Compare Goods and Services Be able to compare and contrast organizations based
on the type of product they make or offer for sale. The Service and Process Classifications
Describe the type of service and the appropriate process classification for it.
Service System Design Matrix Explain the service system design matrix
Blueprint for Service Process Be able to flow chart a service process using
blueprinting
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Service Characteristics and Their Implications on Service Design
ImplicationsCharacteristics
• intangible
• can not be inventoried
• high customer contact
• highly visible to consumers
• production concurrent with
consumption
• labor intensive
• Focus on intangible factors • Capacity planning, flexibility critical
• Less latitude to make mistake
• Problem prevention, process layout, and customer relations
• Location
• Employee treatment and training
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Service Types
Internal Supplier
Internal Supplier
Internal
Customer
ExternalCustomer
Facilities-based vs. Field-based services
Internal Services vs. External Services
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Operational Classification of Services
Amount of customer contact Low vs. High
Service process variability
Standardized vs. customized service
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Service-System Design Matrix
None Low Moderate High
High
Customized clothing
purchase
Moderate
Department store
purchase
LowTelephone purchase
NoneInternet
purchase
Degree of Contact with Customer
Variab
ility in S
ervice Req
uirem
ents
Pro
du
ction
Efficien
cy
low
high
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Service Triangle
The ServiceStrategy
ThePeople
TheSystems
TheCustomer
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Service Strategy: Focus
Treatment of the customer
Speed and convenience
Price
Variety
Quality
Unique skills
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Service Blueprinting: Example
Brushshoes
Applypolish
Failpoint
BuffCollect
payment
Cleanshoes Materials
(e.g., polish, cloth)
Select andpurchasesupplies
Standardexecution time
2 minutes
Total acceptableexecution time
5 minutes
30secs
30secs
45secs
15secs
Wrongcolor wax
Seen bycustomer 45
secs
Line ofvisibility
Not seen bycustomer butnecessary toperformance
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Service Fail-safing
A Proactive Approach Keeping a mistake from becoming a
service defect
Poka-Yokes Simple devices or methods that
prevent mistakes from happening in products or service production
Is this a good poka-yoke?
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Three Contrasting Service Designs
The production line approach Example: McDonalds
The self-service approach Example: ATM
The personal attention approach Example: Ritz Carlton
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Characteristics of a Well-Designed Service System
operating focus user-friendly robust consistent performance evidence of service quality cost-effective effective links between back & front
office
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Tech Note 6: Waiting Line Management Objective: Service Design - Wait Lines
Wait Line Management Identify and explain situations where wait line management is
useful. Apply the principles learned in this lesson to a situation Trade-off between Capacity and Wait Line Cost
Explain why there is a trade-off between capacity and wait lines (be able to asses the cost from the customer and the company’s perspective)
Relationship between Utilization and Wait Time Explain why wait time is longer as facilities get closer to 100 percent
utilization Be able to compare and contrast how wait line management is used
in services and manufacturing with respect to utilization and wait time
Types of Queues Be able to identify the four types of queues and give an example for
each type Problem Solving - Model 1
Be able to calculate the system performance measures given the average number of customers served per time period () and the average number of customers that arrival per time period ()
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Tech Note 6Waiting Line Management
Why waiting lines (queues) unavoidable?
Limited service system capacity – Facilities have a limited amount of space
Variable customer demand -peak v/s non-peak
Why study waiting line? Find the most cost-effective system capacity Goal is to minimize the sum of two costs
Customer waiting costs Service capacity costs
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Wait Line Exercise Using The Target Article
Consider yourself as the manager of the “bateau”:
Given that the bateau is at the dock, what are the constraints for this type of operation?
Where are the potential waiting lines? What is similar and what is different about these lines?
How will you manage the lines to ensure that the business operates successfully and customers are satisfied?
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Some ways to manage wait lines Determine acceptable waiting time for customers Keep customer informed of waiting time Have fast check out lines (segments customers) Schedule customers via a number/ticket,
appointment Run specials to attract customers during non-peak
periods Use experienced/fast workers or faster equipment
to process customers through lines Arrange layout to help process customers through
the service area/try to divert customer’s attention when waiting in line
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Trade-off between Service Capacity & Waiting Line Cost
Totalcost
Customerwaiting cost
Capacitycost= + Cost of
service capacity
Cost of service capacity
Cost of customerswaiting
Cost of customerswaiting
Cost
Service capacity
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Arrival and Service Profiles The number of arrivals can vary
one at a time small groups large groups
The service capacity remains constant size of the facility number of workers during a given shift sometimes capacity is exceeded which
means customers have to wait
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Relationship between Utilization and Waiting Time
0
100
200
300
400
500
600
50% 60% 70% 80% 90% 100%
Utilization
Wa
itin
g T
ime
in
Lin
e
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Components of AQueueing System
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Some Line Structures
ServerSingle channel Single phase
Server2Server1Single channelMultiple phase
Multi-channelSingle phase
S1
S2
S3
Multi-channelMulti-phase
S1
S2
S3
S4
S5
S6
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Components of AQueueing System Customer
from finite or infinite source population single or batch arrivals arrival patterns
Random (Poisson arrivals) Average arrival rate () Average inter-arrival time (1/ )
patient or impatient (balking or reneging)
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Components of AQueueing System
Service System number of lines number of service phases line length (capacity) queue discipline (order of service) number of servers service time
Fixed or random (Exponential service) Average service rate () Average service time (1/ )
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Waiting Line Models
Model LayoutSourcePopulation Service Pattern
1 Single channel Infinite Exponential
2 Single channel Infinite Constant
3 Multichannel Infinite Exponential
4 Single or Multi Finite Exponential
These four models share the following characteristics:
Single phase Poisson arrival FCFS
Unlimited queue length
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System Performance Measures Average number of customers waiting
in line ( ) in system ( )
Average time customers wait in line ( ) in system ( )
System utilization ()
Probability that exactly n customers are in the system (Pn)
lnsn
ltst
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Model 1 Single channel, single phase Poisson arrival (), exponential service ()
)(
2
ln
Major performance measures
sn
)(
lt
1st
n
nP
1
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Application of Model 1Target “bateau” open for business at the dock.Customers arrive at the rate of 25 per hour.The cashier can serve one customer every two minutes.Assume Poisson arrival and exponential service.
A) What is the average utilization of the employee?
B) What is the average number of customers in line?
C) What is the average number of customers in the system?
D) What is the average waiting time in line?
E) What is the average waiting time in the system?
F) What is the probability that exactly two cars will be in the system?
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Application of Model 1 (cont.)
.8333 = cust/hr 30
cust/hr 25 = =
cust/hr 30 = mins) (1hr/60 mins 2
customer 1 =
cust/hr 25 =
A) What is the average utilization of the cashier?
B) What is the average number of customers in line?
4.167 = 25)-30(30
(25) =
) - ( =
22
ln
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Application of Model 1 (cont.)
C) What is the average number of customers in the system?
ns =
- =
25
(30 - 25) =
5
D) What is the average waiting time in line?
mins 10 = hrs .1667 = 25)-030(3
25 =
) - ( =
lt
E) What is the average waiting time in the system?
ts =
- =
1
30 - 25 = .2 hrs =
1
12 mins
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Application of Model 1 (cont.)
F) What is the probability that exactly two cars will be in the system (one being served and the other waiting in line)?
p = (1-n
n
)( )
p = (1- = 2
225
30
25
30)( ) .1157
* What is the probability that an arriving car has to wait?
8333.030/25)30/25)(30/251(11 00 ppw
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Model 2 Single channel, single phase Poisson arrival (), constant service ()
Major performance measures
)(2
2
ln / ls nn
)(2
lt /1 ls tt
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Application of Model 2
An automated pizza vending machine heats and
dispenses a slice of pizza in 4 minutes.
Customers arrive at a rate of one every 6 minutes with the arrival rate exhibiting a Poisson distribution.
Determine:
A) The average number of customers in line.
B) The average total waiting time in the system.
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Application of Model 2 (cont.)
A) The average number of customers in line.
.6667 = 10)-(2)(15)(15
(10) =
) - (2 =
22
ln
B) The average total waiting time in the system.
mins 4 = hrs .06667 = 10)-51)(15(2
10 =
) - (2 =
lt
mins 8 = hrs .1333 = 15/hr
1 + hrs .06667 =
1 + = ls tt
hr/cust10min60
cust10
min6
cust1 hr/cust15
min60
cust15
min4
cust1