CS451 Introduction to Software Engineering

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CS451Introduction to Software Engineering

• Yugi Lee
• FH 560D
• [phone]
• leeyu_at_umkc.edu
• www.sce.umkc.edu/leeyu

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Contents

• Organizational stuff
• Project
• Paper Presentation
• Why software engineering?
• What is software engineering?

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General stuff

• Class M/W 1230 115pm, RHFH460
• Office hours
• M/W 330-430 pm or by appointment

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Course information

• www.umkc.edu/blackboard
• Lecture slides will be available in advance
• Mailing List
• information will be distributed via the mailing
  list (e.g. hints for assignments, corrections
  etc.)

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Textbooks

• Required
• Software Engineering - A Practitioner's Approach
  - Pressman (McGraw Hill), 6th Edition
• Additional readings
• Classical and Object-Oriented Software
  Engineering - Stephen R. Schach (McGraw Hill)
• UML Distilled - Fowler, Scott (Addison Wesley)
• IEEE ACM Magazine Papers

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Course Objectives

• Have a comprehensive picture of software
  development
• Gain hands-on experiences on object oriented
  development in software engineering.
• learn the skill on UML (Unified Modeling
  Language) and tools (National Rose, Project,
  etc).
• learn object-oriented programming (C, Java or
  C) and Web technologies (XML, .NET ASP, etc)
• Understand current trends and requirements of
  software systems and applications.

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Assessment

• Group Project 40
• Individual Work
  60
• Midterm Exam                                     
      15
• Final Exam                                       
          20
• Paper Presentation Discussion              5
• In-Class Exercise Participation             20
  
• Both components must be passed in order to pass
  the course.

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Projects

• Team project
• Teams of 3-4 members
• Development of an entire system following Agile
  software engineering process (feature based
  planning, Unit testing, etc) and OO techniques
  (UML)
• The overall assignment will be divided into
  several steps that will be marked individually.
• Project proposal      
  8
• Skill building Plan                  
  6
• Increments (4)
  16
• Project Report Presentations   
  10
• Being late leads to 10 reduction per day
• Assignments that are submitted more than three
  days late will no longer be accepted.

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Goal of the Team Assignment

• Learning to develop a modular software system
  within a team following an object oriented
  methodology
• Getting a feeling for the (management) problems
  in software development
• Getting an idea of your own productivity
• Having group work experience (work-with-other)

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Team Assignment

• The software should be developed following basic
  software engineering principles
• processes analysis, design, implementation,
  review, and testing phases
• products requirements and design documents,
  source code, review results, test cases, test
  results, and productivity metrics

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Potential Projects

• A community partner - developing a software or a
  database system to track the children in their
  after school programs.

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Exams (Tentative Schedule)

• Midterm exam 3/27/06
• Final examination Final exam period
• Covers the whole course but will focus on
  the second part

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Paper Presentation

• Each student presents one or two papers
• about 20 minutes
• sign-up schedule
• actively involved in discussion
• IEEE Magazines i.e., Internet Computing, Computer
• ACM Magazine Communications

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Introduction to Software Engineering
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What is Software? Pressman

• Software is a set of items or objects
• that form a configuration that
• includes
• programs
• documents
• data ...

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Softwares Dual Role Pressman

• Software is a product
• Delivers computing potential
• Produces, manages, acquires, modifies, displays,
  or transmits information
• Software is a vehicle for delivering a product
• Supports or directly provides system
  functionality
• Controls other programs (e.g., an operating
  system)
• Effects communications (e.g., networking
  software)
• Helps build other software (e.g., software tools)

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Why Software Engineering?

• ...to get away from ad hoc and unpredictable
  software development towards a systematic,
  understood one...

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Characteristics of Todays Software Development

• Development of large complex systems
• Software systems must fulfill the requirements of
  a client
• Number of persons involved in the development gt
  1
• Software systems are expected to live long and be
  used by many people

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What are the Problems?

• Increased quality demands on software products
• High cost and time pressure
• Shorter time to market
• Coordination problems within the projects
• Scarce resources

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The Software Crisis and Solution

• 1968 NATO conference in Garmisch-Partenkirchen
• software crisis (to characterize the situation)
• software engineering (idea for a solution)

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Why still Software Engineering?

• Has the software crisis vanished?
• No!
• Software projects still run over time and out of
  budget
• no break through in quality !!!still art
  instead of engineering discipline

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Software Crisis?

• Unacceptably low quality of software
• Delayed deadlines Average 1 year

• Over cost limits Average 2X estimate
• E.g. Air Force Command and Control system
• Initial estimate
• 1.5million
• Winners bid
• 0.4 million
• Actual cost
• 3.7 million

• After deliver?
• E.g. U.S Army study of
• Federal projects
• Delivered, but not used 47
• Paid for, but not delivered 29
• Abandoned or reworked 19
• Used after changes 3
• Used as delivered
• 2

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Practical Disasters

• European Space Agency Ariane 5
• Track control system failure results in self
  destruction
• Denver Airport
• Late delivery of software for the baggage system
  delays the opening of the airport by 16 months
• US study (1995) 81 billion US spend per year
  for failing software development projects

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Why is Software so Hard?

• Software is Parnas, 1985
• Buggy
• Unreliable
• Forever changing
• Unwarrantable

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Legacy Software

• Why must it change?
• software must be adapted to meet the needs of new
  computing environments or technology.
• software must be enhanced to implement new
  business requirements.
• software must be extended to make it
  interoperable with other more modern systems or
  databases.
• software must be re-architected to make it viable
  within a network environment.

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Management Myths

• State-of-the-art tools are the solution
• A fool with a tool is still a fool
• Getting behind schedule resolved by hiring
  additional programmers
• adding people to a late software project makes
  it later

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Management myths
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Customer Myths

• A general statement of objectives is sufficient
  to begin writing programs - we can fill in
  details later.
• Thorough communication between customer and
  developer needed
• Changes can be easily accommodated because
  software is flexible
• changes happen as a fact of life
• late changes are expensive

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The Impact of Change
Cost to change
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Practitioners Myths

• Once we write a program and get it to work, our
  job is done
• 50-70 of all effort after first delivery
• Until I get the program running, I really have
  no way in assessing its quality
• inspections reviews
• The only deliverable for a successful project is
  the working program
• documentation (users, maintenance)

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Definition Software Engineering

• Software Engineering (1) The application of a
  systematic, disciplined, quantifiable approach to
  the development, operation, and maintenance of
  software that is, the application of engineering
  to software. (2) The study of approaches as in
  (1) IEEE-93

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Three Ps
People
Processes
Products
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People, Processes, Products

• People
• education
• skills
• communication
• style
• .....

• Products
• requirements
• design
• source code
• executable
• user documentation
• test cases
• test results
• change request
• ....

• Processes
• planning
• coordination
• management
• measuring
• analyzing
• designing
• coding
• .....

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Scope Software Engineering

• extremely broad
• the software life cycle
• team or organization
• economic aspect
• legal aspect,
• etc.

• various disciplines
• Mathematics,
• Computer science,
• Economics,
• Management,
• Psychology
• etc.