CS4510: Software Engineering
Laurie Williams
Graduate Student
Course Objectives

To further your knowledge of process-based approaches to
developing software for high-quality software products (xSP)
– (1-person) Individual based (Personal Software Process)
– (2-person) Collaborative team based (Collaborative Software Process)
– (4-person) Team based (Team Software Process)

To gain further knowledge of important Software Engineering
techniques

Your future employer will most likely follow A process which
will consist of various combinations of what we will be
learning . . . the main lesson here is that it is important to know
how to follow a process.
Software Engineering Techniques

Object Oriented Software Engineering
– Unified Modeling Language (UML)
– Rational Rose tool
– CRC Cards
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Software Measurements
Design and Code Reviews
Quality Management
Testing
Software Planning and Estimating
The Team Software Process (TSP)
NOTE: It is intended that the assignments will not be so big that
you end up abandoning these new software engineering
techniques “just to get done”
Grade Distribution

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(Visual C++) Programming Assignments (40%)
(Visual C++) Team Project (20%)
Midterm (20%)
Final (20%)
General Information

Prerequisites
– Quarter sequence: CS354-CS355-CS356
OR
– Semester course: CS3500

Book / Materials
– Required: “Adult” PSP Book “A Discipline for Software Engineering”
– Required: “Introduction to the Team Software Process”
– Arriving in a shrink-wrapped pack to the bookstore any day

Collaboration vs. Individual Work
– Class will be curved according to groups, if need be.
– The Institutional Review Board (IRB) has looked out for you!
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Schedule
– Tues. class in this classroom (EMCB 110)
– Thurs. class in NT lab (EMCB 210)
» (Mandatory) Free lab time to work on your assignments
– (Mandatory) Two hours/week additional lab time . . .we’ll be working
out schedule
It’s All About Motivation

WIIFY
– A teacher who’s research is your class and will work to make
everything just right.
– Experience with leading edge software development techniques
– Get to do 1 ½ hour’s worth of homework on class time
– A guaranteed computer in the lab (for two hours) when you get
there
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WIIFM
– Graduation . . . so I can finally be a “real professor” and teach
people like you for the rest of my life
Tidbits/Standard Stuff
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Development Language/Environment: Visual C++
Class web page:
– http://www2.cs.utah.edu/classes/cs4510
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Class lecture notes linked off the web
– Will be there by noon (hopefully 10AM) day of class for you to print
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Class mailing list:
– subscribe to cs4510
» (majordomo@cs)
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Class/lecture philosophy (borrowed from medical school):
– “See one, do one, teach one”
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My Office Hours TBD
TA (Tao Hu) Office Hours TBD
Today’s Lecture
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A “Process” Perspective
GQM Paradigm
Analysis: Use Cases
Process and Profession
Dennis J. Frailey
What Do These Words Mean?
Regulation
Order
Loss of Creativity
Safety
Meddling
“Police”
PROCESS
PROFESSION
Responsibility
Organization
Doom and Gloom
Consistency
End of the World
Reliability
The Way it Was
Software Developers
The Public
Who Cares!
Protective Cloak of Technology
and Nerdliness
The Way it Is Becoming
Why does this
software crash all
the time?
My pacemaker
has a
computer!
Who should we sue
for this fiasco?
Software Engineering
Black Art
Profession
Good Things I Have Seen
with Process Focus
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More Accurate Estimates
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Software that does Not Crash (at least not often :-)
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Higher Productivity
…
Bad Things I Have Seen
with Process Focus
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Overly Prescriptive Interpretations
People wanting a Cookbook instead of a Model
Dehumanization of Software Development
Process Blamed because it is not a “Silver Bullet”
...
Employees Leaving because they Don’t Like the Climate (i.e.
dropping the class)
Proper Use of Process
(and Professionalism)

Education and Understanding are the Keys to
Effective and Proper Use
– True professionals in any field always have good processes
and practices
» Even if they don’t use that terminology
– They know how to make effective use of good processes and
practices
– And they know when the processes and practices do not apply
“Take Aways”

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We need to be professionals
We need to follow a process
– Could be PSP, CSP . . . or whatever
– Alternative: Ad hoc (Black Art)
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Need to understand the process enough to know
when it it is prudent to apply and when it is not
– Programmer
– Management
when it it is prudent to apply and
when it is not . . .
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“I know I should be doing a more thorough design
but I really don’t feel like it.”
“I’ve been programming for years now, and I forgot
one silly semicolon. It’s really not worth the time to
record this defect.”
“Note that any predefined process must be an
approximation, so some of the exercises in this
book may be more helpful to you than others. After
you have practiced them all, you will be able to
decide which to use and when. Apply the PSP
principles where you feel they will help.”
– It is a PERSONAL software process . . . It presents many useful
techniques, try them and then do what works for you
PSP Compile Time Range
% of Total Time
35
30
25
Max
20
Avg
15
Min
10
5
0
1
2
3
4
5
6
7
8
Program Number
9
10
Defects/KLOC
(PSP) Defects Found in Test Range
200
180
160
140
120
100
80
60
40
20
0
Max
Avg
Min
1
2
3
4
5
6
7
8
Program Number
9
10
LOC/Hour
PSP Productivity Range
100
90
80
70
60
50
40
30
20
10
0
Max
Avg
Min
1
2
3
4
5
6
7
8
Program Number
9 10
Goal - Question - Metric (GQM)
Paradigm
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Define the principle goals for your activity
Construct a comprehensive set of questions to help
you achieve these goals
Define and gather the data required to answer these
questions
Goals
It’s ALL about
GOAL
WIIFM
What’s standing in your way / What do you need to do to
achieve this?
How will you know when you accomplished this?
Question
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Make “vague goals” more concrete
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For each process goal, where did I start, where am I
going now, and where do I want to go?
– How fast can I run now? How fast do I want to run?
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What is important about this goal?
– WIIFM?
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What the best that has been achieved against this
goal?
Metrics
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To explicitly and efficiently answer the questions
(which relate to the goals)
Data gathering takes time . . . It’s all about motivation!
The data can effect your performance
– “Hawthorne effect” whereby behavior changes depending on what
is measured
– Best if these software measurements can be personal
» In this class, your grade WON’T be based on how fast you code
or how many defects you have (as long as you remove them!!)
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All I really care about is that you are entering data accurately so that you can
learn the lessons of the class
» Ideally, this will be the case in industry too
A GQM Example
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Goal: To produce programs that contain no defects
Question: How can you produce software of such
quality that no defects will be found later in test?
Metrics:
– No way to GUARANTEE that you have produced an error-free
product.
– With sufficient data and a suitably controlled process you can
improve the likelihood that your program is error-free
– Define a strategy for deciding when a program is of high enough
quality to be released, if it should be reappraised, or if it should
be scrapped and re-engineered . . . Garbage In, Garbage Out
(GIGO)
» # of defects removed in Code Review
» # of defects in test
Object Oriented Software Engineering:
Requirements Analysis
Planning, estimation, organization,
process, management, ...
System
engineering
Analysis
Design
Coding
Testing
Maintenance
Configuration control, metrics,
defect tracking, reuse, documentation, ...
“How to figure out what it is that you
should be doing, before you start doing
what it is that you should be doing.”
CS 451
L13 - 28
Goals of Performing Analysis
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To understand the problem or problems that the
eventual software system should solve
To prompt relevant questions about the problem
and the system
To provide a basis for answering questions about
specific properties of the problem and system
To decide what the system should do
To decide what the system should not do
To ascertain that the system will satisfy the needs of
its users, and define acceptance criteria
To provide a basis for the development of the
system
Visual Modeling
(from Terry Quatrani: Visual Modeling with Rational Rose and UML)

A way of thinking about problems using models
organized around real-world ideas
– We can visualize them in our head

To promote a better understanding of requirements,
cleaner designs, and more maintainable systems

We build models because we cannot comprehend
such systems in their entirety
– Focus on the big picture of how a project’s components interact
– Without getting bogged down in the specific details of each
component
The Triangle for Success
Notation: Unified Modeling Language (UML)
Process: PSP/CSP/TSP
Tool: Rational Rose
External System Behavior: Use Case Model
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Complete course of events in the system, from the
user’s perspective
Use Cases Model: Illustrates
– (use cases) the system’s intended functions
– (actors) surroundings – external to the system
– (use case diagrams) relationships between use cases and actors

Use Case Model is an important communication
vehicle between customers (they can understand it!)
and developers
The collection
of all use
cases is
everything
that can be
done to/with
the system
Actors
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Are NOT part of the system – they represent anyone
or anything that must interact with the system
– Only input information to the system
– Only receive information from the system
– Both input to and receive information from the system
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Represented in UML as a stickman
A Case Study:
Eastern State University
(ESU) Registration Problem: Background
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After professors decide which courses they will teach, the Registrar
enters in info in the computer
A course catalog is printed and distributed to students
Students fill out form with their choices – usually 4 courses
Registrar enters this info into computer
A batch job is run overnight to assign students to courses
In cases of conflict where the students cannot take the classes they
had selected, the registrar contacts the students directly to obtain
additional choices.
Once all students have successfully assigned to courses, a
hardcopy of the schedule is sent to the student.
Professors obtain student rosters for their classes.
Eastern State University (ESU) Registration
Problem: Problem Statement
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Professors indicate which courses they will teach on-line.
A course catalog is printed
Allow students to select on-line four courses (and two
additional choices) for upcoming semester.
No course may have more than 10 students (this is not the U!)
or less than 3 students.
When the registration is completed, the system sends
information to the billing system.
Professors can obtain course rosters on-line.
Students can add or drop classes on-line.
Who are the actors??
Use Case

A sequence of transactions performed by a system that yields
a measurable result of values for a particular actor
– What are the tasks of each actor?
– Will any actor create, store, change, remove or read information in the
system?
– What use cases will create, store, change, remove or read this
information?
– Will any actor need to inform the system about sudden, external changes?
– Does any actor need to be informed about certain occurrences in the
system?
– What use cases will support and maintain the system?
– Can all functional requirements be preformed by the use cases?

A use case typically represents a major piece of functionality
that is complete from beginning to end. A use case must
deliver something of value to an actor.
What are the uses cases in the ESU Course
Registration System??
Flow of Events for a Use Case
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Description of the events needed to accomplish the
required behavior of the use case. Written in terms
of what the system should do, not how the system
does it
–
–
–
–
–
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When and how the use case starts and ends
What interaction the use case has with the actors
What data is needed by the use case
The normal sequence of events for the use case
The description of any alternative or exceptional flows
Done in an iterative manner.
– First just the normal flow of the use case
– More details
– Exceptional flows added
Template for Flow of Events
X Flow of Events for the <name> Use Case
X.1 Preconditions
X.2 Main Flow
X.3 Subflows (if applicable)
X.4 Alternative Flows
Where X is a number from 1 to the number of use cases
IMPORTANT: Be flexible – do what’s appropriate for the
use case.
UML Relationships

Between Actor and Use Case
– Association / Communication
– Arrow can be in either or both directions
– Arrow indicates who initiates
communication

Between Use Cases (Generalization):
– Uses
» Where multiple use cases share
pieces of same functionality
– Extends
» Optional behavior
» Behavior only run under certain
conditions (such as alarm)
» Several different flows run base on
user selection
Stereotypes
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Provides the capability to extend the basic modeling
elements to create new elements
Allows the UML to have a minimal set of symbols
that may be extended where needed to provide the
communication artifacts that have meaning for the
system under development
Included within << >> and placed along the
relationship line
–
–
–
–
<< Communicates >>
<< Extends >>
<< Uses >>
Define your own . . .