___________________________________ ___________________________________ PMBA8155 Operations Management
___________________________________ ___________________________________ Process Analysis
___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ Learning Objectives

___________________________________ Understand
___________________________________ Process flowcharting
• Types of Process:
•
___________________________________  multistage vs. single stage
 make-to-order vs. make-to-stock
•

___________________________________ Blocking vs. starving
___________________________________ Understand and Calculate Various
Measures of Process Performance
2
___________________________________ ___________________________________ What Is A Process?
___________________________________ A process is a collection of activities that
transforms inputs into outputs that are
valuable to the customer
 Any part of an organization that takes inputs
and transforms them into outputs is a process


___________________________________ ___________________________________ ___________________________________ Process analysis is to systematically examine
all aspects of a process to improve its
operations with regard to cost, quality, speed,
and responsiveness
___________________________________ 3
___________________________________ ___________________________________ Process Flowchart

___________________________________ Diagram showing the major elements of a
process and their interconnections
___________________________________  tasks
or operations
___________________________________  flows
of materials or customers
___________________________________  storage
areas or queues.
___________________________________ 4
___________________________________ Process Flowchart
___________________________________ Symbols
___________________________________ ___________________________________ Storage areas or
queues
Tasks or operations
___________________________________ ___________________________________ Flows of materials
or customers
Decision Points
___________________________________ 5
___________________________________ Process Flowchart
___________________________________ Examples:
Hamburger Making Process
Raw
material
Cook
___________________________________ Customer
order
1. McDonald’s
Finished
burgers
Assemble
2. Burger King
___________________________________ Deliver
___________________________________ Assemble
C
Raw
material
Cook
WIP
Customer
order
Assemble
Customer
order
Raw
material
Cook
Custom
or
Standard?
S
___________________________________ Deliver
Finished
burgers
___________________________________ 3. Wendy’s
Assemble
Deliver
Chili
6
___________________________________ ___________________________________ Types of Processes

___________________________________ Single-stage vs. Multistage
___________________________________ ___________________________________ Stage 1
___________________________________ ___________________________________ Stage 1
Stage 2
Stage 3
7
Types of Process
Stage
1
Buffer
___________________________________ Stage
2
Multistage Process with Buffer

What might happen without buffers?



Blocking: occurs when the activities in a stage
must stop because there is no place to deposit
the item (Stage 1 when it is faster)
Starving: occurs when the activities in a stage
must stop because there is no work (Stage 2
when it is faster)
___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ Bottleneck: the stage that limits the capacity
of the process (the slowest stage)
8
___________________________________ Types of Process
___________________________________ Make-to-stock vs. Make-to-order
Make
___________________________________ Customer
order
Make-to-stock Process
Finished
goods
___________________________________ ___________________________________ Deliver
___________________________________ Customer
order
Make
Make-to-order Process
___________________________________ Deliver
9
___________________________________ Types of Process
___________________________________ Paced vs. Non-paced

Pacing refers to the fixed timing of the
movement of items through the process

Assembly lines are often paced (e.g.
every 30 seconds, there is a movement
of items from stage to stage)

___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ Most service processes are non-paced
10
___________________________________ “You can not improve what you can’t measure”
___________________________________ Process Performance Metrics
___________________________________ 
Operation time = Setup time + Run time
___________________________________ 
Flow time = Average time for a unit to move
___________________________________ through the system

___________________________________ Cycle time = Average time between completion
___________________________________ of successive units

Throughput rate =
1
Cycle time
11
___________________________________ Important Notice Regarding the
Use of Performance Measures
 These measures are designed to be used when
a production system has reached steady state
 A steady state is the state of the system when
the system characteristics such as production
rate do not change over time
 Typically, the steady state is reached after the
system has been in operations for some time
•
___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ For example, the production rate at the beginning of
the day when the system is idle is different than
when the system has been operated for a while
12
___________________________________ ___________________________________ Process Performance Metrics
___________________________________ Example 1
___________________________________ 3 min/unit
3 min/unit
3 min/unit
Stage 1
Stage 2
Stage 3
___________________________________ ___________________________________ (Assume 8-hour working day)
Flow time = 3 + 3 + 3 = 9 minutes
___________________________________ Cycle time = 3 minutes
___________________________________ Throughput rate = 1/3 units/min = 20 units/hr
= 120 units/day
13
___________________________________ Process Performance Metrics
___________________________________ Example 2
___________________________________ 2 min/unit
3 min/unit
1 min/unit
Stage 1
Stage 2
Stage 3
___________________________________ ___________________________________ (Assume 8-hour working day)
Cycle time = 3 minutes
___________________________________ Throughput rate = 120 units/day
___________________________________ Flow time = 3 + 3 + 1 = 7 minutes
14
___________________________________ Process Performance Metrics
___________________________________ Example 3
2 min/unit
Stage 1
Buffer
___________________________________ 3 min/unit
1 min/unit
Stage 2
Stage 3
___________________________________ ___________________________________ (Assume 8-hour working day)
Cycle time = 3 minutes
Throughput rate = 120 units/day
___________________________________ Flow time = A fairly big number
___________________________________ At the end of the day, how many items are in
the buffer? = (1/2 – 1/3) x 60 x 8 =80
15
Demonstration 1
___________________________________ A
2
Min
1
2
3
4
A
Unit 1
5
6
B
7
8
9
(No Buffer)
C
1
___________________________________ 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
___________________________________ C
A
Unit 2
B
3
B
B
C
A
Unit 4
B
C
A
Unit 5
B
___________________________________ C
A
Unit 6
___________________________________ Cycle time = 3 min
TPR= 20 units/hr
TPT= 7 min
C
A
Unit 3
B
___________________________________ C
A
Unit 7
B
C
A
Unit 8
B
___________________________________ C
A
Unit 9
B
C
Lesson 1: The throughput rate (capacity) of a
process is determined by the bottleneck stage, not
the flow time
Demonstration 2
___________________________________ A
2
Min
1
2
3
4
A
Unit 1
5
6
B
7
8
9
10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
B
B
C
A
Unit 4
Cycle time = 3 min
TPR= 20 units/hr
TPT gets longer over time
C
A
Unit 3
(With Buffer)
C
1
___________________________________ ___________________________________ C
A
Unit 2
B
3
B
C
A
Unit 5
B
B
___________________________________ C
A
Unit 7
B
A
Unit 8
C
B
___________________________________ C
A
Unit 9
___________________________________ C
A
Unit 6
___________________________________ B
C
Lesson 2: Adding buffer (inventory holding area)
doesn't change the capacity of a process but can
make it slower in terms of the flow time
___________________________________ In-Class Exercise
___________________________________ Driver License Renewals
Review
Payment
Check
Violations
Eye Test
Photograph
Issue
license
15 sec
30 sec
60 sec
40 sec
20 sec
30 sec
___________________________________ ___________________________________ ___________________________________ 




How many applications per hour can be Reviewed?
What is the cycle time of this process?
What is the process throughput rate per hour?
If two buffers are added right before and after Check
Violations, how many applicants will be in after one hour
of operations?
How many applications can be processed per hour if a
18
second clerk is added to check for violations?
___________________________________ ___________________________________