EECE 310: Software Engineering

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EECE 310 Software Engineering

• Course Orientation

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How are we doing? SW Project Success
Successful
16
Cancelled
31
Challenged
53
Source Standish Group, Chaos report, 1995
3
Course orientation

• What is this course about?
• Where can I find the course syllabus and other
  stuff?
• http//www.ece.ubc.ca/matei/EECE310/
• we will NOT use WebCTl
• What will I learn in the course?
• What do I need to do to pass the course?
• What do I need to do to get 90 in the course?
• How do I contact/see the course staff?
• Office hours
• How can I obtain latest announcements regarding
  the course?

4
Course orientation (cont.)

• What background should I have?
• What will I be doing in the course?
• Project / Assignments
• Quizzes
• Final exams
• Reading
• Participation
• What will I be reading?
• What will the course schedule look like?
• Where can I find additional information
  resources?
• How can I provide feedback?

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Instructors T.A.

• Instructor Matei Ripeanu -- http//www.ece.ubc.ca
  /matei/
• matei_at_ece.ubc.ca
• Research interests Distributed systems
• Peer-to-peer, Grid systems, utility computing
• Large scale online games
• Distributed storage systems
• Collaborative information/content sharing
  tagging, video-sharing
• High-performance scientific computing
• Use of novel technologies to accelerate
  computation
• Networking
• Teaching Assistants
• Armin Bahramshahry -- armin.ece.ubc_at_gmail.com
• Abdullah Gharaibeh -- abdullah_at_gmail.com

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about Software Engineering

• Application of a systematic, disciplined,
  quantifiable approach to the development,
  operation, and maintenance of software (IEEE
  1990)
• Multi-person construction of multi-version
  software (Parnas 1978)
• Software engineering ? Programming
• Building software-intensive systems

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Software engineering sub-disciplines

• Software Requirements
• Software Design
• Software Construction
• programming
• Software Testing
• Software Quality

• Software configuration management
• Software engineering management
• Software engineering process
• Software engineering tools and methods
• Software maintenance

Main focus of this course
Overview
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After this course you will be able to

• specify a software component and its properties
• design it and describe the design using UML
• select appropriate design patterns
• implement it (in different programming languages)
• verify that both the design and the
  implementation meet its specification
• document it for later evolution by others
• fit all these activities in the framework of a
  software development lifecycle
• select and use the appropriate tools for the tasks

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What will you do in this course?

• Lectures
• Reading
• Quizzes/Final exam
• Project/Assignments
• Labs
• Grading scheme
• 50 project assignments
• 45 quizzes final exam
• 5 class participation

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Reading textbook, etc.

• Textbook
• Barbara Liskov with John Guttag, Program
  Development in Java Abstraction, Specification,
  and Object-Oriented Design, Addison-Wesley
  Professional. First Edition. ISBN 0201657686
• Available in UBC bookstore
• Not followed 100 in class by instructors
• Recommended reading
• See class webpage for a few useful pointers on
  books, and for papers to download and read.

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Class webpage http//www.ece.ubc.ca/matei/EECE31
0/

• Syllabus
• Calendar
• and last minute announcements
• Assignments
• Additional reading material
• Course hand-outs

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Mailing list eece310_at_ece.ubc.ca

• Discussions
• Asynchronous communication with peers, TA and
  instructors
• The 1st place to ask questions (and answer them)
• How do I subscribe
• email sympa_at_ece.ubc.ca with subscribe
  eece310_at_ece.ubc.ca in the body of the message,
  or
• visit https//lists.ece.ubc.ca/

13
Project

• Chat system
• Some handholding multiple stages
• Technologies Java, Eclipse, version control
  system, JUnit, UML
• Component trading!
• Grading scheme (out of 100 for the whole
  project)
• 10 specification
• 10 project presentation
• 70 correctness, design, documentation of various
  phases
• 10 critique of other two projects
• 5 bonus if someone uses your project in the next
  phase
• 5 bonus points teamwork
• Groups of up to four

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Note on Plagiarism

• Exams / quizzes are individual, closed book
• Automated detection of plagiarism in code
• Consequence Exclusion from UBC for 2 years (both
  parties, copier and copied)

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Questions?
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About Programming Languages

• Course EECE310 not about programming
• However, a good software engineer is comfortable
  with several programming languages, and able to
  learn new ones.
• No language bigotry, no OS bigotry
• Brief Java review in class for thenext two classes

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About Software Tools

• Eclipse environment for Java
• UML tool Rational Rose
• Documentation tool Doxygen
• Testing JUnit
• Source control CVS/SVM/Perforce

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Outline

• Instructors
• Software engineering
• Syllabus
• Textbook
• Tools
• Evaluation, exams, attendance
• Agenda details
• Plagiarism

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EECE 310 Software Engineering

• Overview of Software Engineering

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Some Facts on Software Engineering

• The economies of ALL developed nations are
  dependent on software.
• More and more systems are software controlled
• Software engineering is concerned with theories,
  methods and tools for professional software
  development.

Source Ian Sommerville, 2004
21
Some Facts on Software Costs

• Software costs often dominate computer system
  costs. The costs of software on a PC are often
  greater than the hardware cost.
• Software costs more to maintain than it does to
  develop.
• For systems with a long life, maintenance costs
  may be several times development costs.
• Software engineering is concerned with
  cost-effective software development.

Source Ian Sommerville, 2004
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Objectives of this Module

• What is software?
• What is software engineering?
• What are the key questions software engineers are
  faced with?
• A brief history of Software Engineering
• What have we learned from our short history?

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What is Software?

• Computer programs and associated documentation
  such as requirements, design models and user
  manuals.
• Software products may be
• Generic - developed to be sold to a range of
  different customers in a general market (e.g. PC
  software such as Excel or Word.)
• Custom - developed for a single customer
  according to their specification.
• New software can be created by developing new
  programs, configuring generic software systems or
  reusing existing software.

Source Ian Sommerville, 2004
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What is Software Engineering?

• Multi-person construction of multi-version
  software (Parnas, 1978)
• Software engineering engineering discipline
  concerned with all aspects of software production
  (Sommervile, 2004) .

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Building a doghouse vs. building a skyscraper
?
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Issues

• Scale
• Time
• Cost
• Risks
• Number of people involved
• Number of different stakeholders
• Methods
• Liabilities

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A Wide Range of Complexity Issues
Higher technical complexity - Embedded,
real-time, distributed, fault-tolerant - Custom,
unprecedented, architecture reengineering - High
performance
Higher management complexity - Large scale -
Contractual - Many stake holders - Projects
Lower management complexity - Small scale -
Informal - Single stakeholder - Products
Lower technical complexity - Mostly 4GL, or
component-based - Application reengineering -
Interactive performance
Source Walker Royce, 1995
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Software engineering sub-disciplines

• Software Requirements
• Software Design
• Software Construction
• programming
• Software Testing
• Software Quality

• Software configuration management
• Software engineering management
• Software engineering process
• Software engineering tools and methods
• Software Maintenance

Software Engineering Body of Knowledge
Source www.swebok.org
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Software Engineering vs. Computer Science?

• Computer Science is concerned with theory and
  fundamentals
• Software Engineering is concerned with the
  practicalities of developing and delivering
  useful software.
• Computer science theories are still insufficient
  to act as a complete underpinning for software
  engineering.

Source Ian Sommerville, 2004
30
Software Engineering vs. System Engineering?

• System engineering is concerned with all aspects
  of computer-based systems development including
  hardware, software and (business) process
  engineering.
• Software engineering is part of this process
  concerned with developing the software
  infrastructure, control, applications and
  databases in the system.
• System engineers are involved in system
  specification, architectural design, integration
  and deployment.

Source Ian Sommerville, 2004
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What is a system?

• A purposeful collection of inter-related
  components working together to achieve some
  common objective.
• A system may include software, mechanical,
  electrical and electronic hardware and be
  operated by people.
• System components are dependent on other system
  components
• The properties and behaviour of system components
  are inextricably inter-mingled

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How are we doing? SW Project Success
Successful
16
Cancelled
31
Challenged
53
Source Standish Group, Chaos report, 1995
33
Failure factors

• Lack of user input
• Incomplete requirements
• Constantly changing requirements
• Lack of management support
• Technology incompetence
• Lack of resources
• Unrealistic expectations
• Unclear objectives
• Unrealistic timing
• New Technology

Source Standish Group, Chaos report, 1995
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Success Factors?

• User involvement
• Clear statement of requirements
• Management support
• Proper planning
• Realistic expectations
• Smaller milestones
• Competent staff
• Ownership
• Clear vision
• Hard working staff

What made the 16 of projects successful ?
Source Standish Group, Chaos report, 1995
35
What about Quality?

• What we can get away with
• Good enough software
• Not applicable to all types of software though
• When good enough is close to perfect for safety
  critical systems
• Ethical issues
• Cultural and social issues
• Competitive issues

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Software Crisis

• Seems that it last forever, though
• 1968
• 1976
• 1980
• 1994
• 2001

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Summary (last lecture)

• Software engineering not very successful
• Poor rate of success
• Poor quality
• Profession in a state of permanent crisis
• (since the 1960s)
• Issues?
• Requirements and specifications
• Complexity
• Time to market
• Communications
• Technology churn
• Education

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Last time success rate for large software
development projects
Successful
16
Cancelled
31
Challenged
53
Source Standish Group, Chaos report, 1995
39
Is this a good industry to be in?
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Brief History of Software Engineering (1)

• Antiquity
• 1950 1968 Big irons (software is free!)
• 1968 NATO conference in Germany
• Identification of a software crisis
• Start of the quest for a better way (silver
  bullet)
• Term Software engineering used
• The search of a Silver Bullet, of the Grand
  narrative
• 1960 1990 programming languages
• 1970 1980 introduction of methods
• 1985 - CASE tools PSEs and IDEs
• 1990 - Object-oriented technologies
  middleware

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Brief History of Software Engineering (2)

• Post-modern era (Internet age)
• no grand narrative no silver bullet
• its all good.
• 1996 - Agile methods
• as a reaction to many of the process and methods
  excesses
• Next?
• The end of programming?
• Model-driven development?
• Scrap-heap software development?

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What are Software engineering methods?

• Structured approaches to software development
  which include system models, notations, rules,
  design advice and process guidance.
• Model descriptions
• Descriptions of (graphical) models which should
  be produced
• Rules
• Constraints applied to system models
• Recommendations
• Advice on good design practice
• Process guidance
• What activities to follow.

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CASE (Computer-Aided Software Engineering) ?

• Software systems that are intended to provide
  automated support for software process
  activities.
• CASE systems are often used for method support.
• Upper-CASE
• Tools to support the early process activities of
  requirements and design
• Lower-CASE
• Tools to support later activities such as
  programming, debugging and testing.

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What are the attributes of good software?

• The software should deliver the required
  functionality and performance to the user and
  should be maintainable, dependable and
  acceptable.
• Maintainability Software must evolve to meet
  changing needs
• Dependability Software must be trustworthy
• Efficiency Software should not make wasteful use
  of system resources
• Acceptability Software must accepted by the
  users for which it was designed. This means it
  must be understandable, usable and compatible
  with other systems.

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Key challenges facing software engineering?

• Heterogeneity
• Developing techniques for building software that
  can cope with heterogeneous platforms and
  execution environments
• Delivery
• Developing techniques that lead to faster
  delivery of software
• Trust
• Developing techniques that demonstrate that
  software can be trusted by its users
• Plus Ethical issues, cultural issues, social
  issues

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Suggested reading

• Fred Brooks, No Silver Bullet-Essence and
  Accident in Software Engineering, 1986
• Standish Group, Chaos Report 1995 Extreme Chaos,
  2001
• W. Gibbs, Softwares Chronic Crisis, Scientific
  American, 1994
• Daniel Berry, The Inevitable Pain of Software
  Development Why There Is No Silver Bullet,
  Workshop on Radical Innovations of Software and
  Systems Engineering in the Future, 2002
• Ph. Kruchten, Casting software design in the FBS
  framework, IEEE Software

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Next Quick Java review

• Program structure
• classes, interfaces
• Packages
• Objects and variables
• Mutability
• Method call semantics
• Type checking
• Type hierarchy
• Conversion and overloading
• Dispatching
• Types
• Primitive object types
• Vectors
• Hello world

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• public class Num
• // provides useful numeric routines
• public static int gcd (int n, int d)
• // REQUIRES n and d greater than 0
• // RETURNS the GCD computed by repeated
  substraction
• while (n ! d)
• if (ngtd) nn-d else dd-n
• return n
• public static boolean isPrime (int n)
• // REQUIRES
• // RETURNS
• .

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• 1 /
• 2 This program computes the factorial of a
  number
• 3 /
• 4 public class Factorial //
  Define a class
• 5 public static void main(String args) //
  The program starts here
• 6 int input Integer.parseInt(args0) //
  Get the user's input
• 7 double result factorial(input) //
  Compute the factorial
• 8 System.out.println(result) //
  Print out the result
• 9 //
• 10
• 11 public static double factorial(int x) //
  This method computes x!
• 12 if (x lt 0) //
  Check for bad input
• 13 return 0.0 //
  if bad, return 0
• 14 double fact 1.0 //
  initial value
• 15 while(x gt 1) //
  Loop until x equals 1
• 16 fact fact x //
  multiply by x each time
• 17 x x - 1 //
  and then decrement x
• 18 //
  Jump to start of loop