CPSC 333 SENG 311: Foundations of Software Engineering

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CPSC 333 / SENG 311 Foundations of Software
Engineering
Instructors Dr. Rose Joshua, ICT
548 joshuar_at_cpsc.ucalgary.ca Office Hours MTW
12-1pm Dr. Rob Walker, ICT 546 rwalker_at_cpsc.ucalg
ary.ca Office Hours WF 1-2pm
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Contents / Reading List

• Organizational stuff
• Why software engineering?
• What is software engineering?
• Read Pressman, Chapter 1

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General Information

• Labs start on Mon/Tue, Sept. 15, 2003.
  Participation in the first lab is absolutely
  required

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Course information

• http//sern.ucalgary.ca/Courses/CPSC/333/ f03/ind
  ex.html
• Slides will be available after each class
• Newsgroup cpsc.courses.cpsc333
• Use your news reader to subscribe (e.g. Netscape)
• information will be distributed via the mailing
  list (e.g. hints for assignments, corrections
  etc.)

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Textbooks

• See your Course Info Sheet
• Pressman Software Engineering A Practitioners
  Approach, 2001 (5th. Edition).
• Beck Fowler Planning Extreme Programming,
  2000.
• Fowler Scott UML Distilled, 1999.
• Beck Extreme Programming Explained, 1999.

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Assessment

• Lab
• Individual Assignments 9
• Group Assignments 31
• Exams
• Mid-Term Exam 20 Friday, Oct. 17th, 6pm, ST
  140
• Final exam 40
• Both components must be passed in order to pass
  the course.

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Assignments

• Team project
• Teams of 6 8 members
• Every team will develop their own system.
• The overall assignment will be split into three
  iterations that will be marked individually
• Individual Assignments TBA
• No late submissions will be accepted. Late
  submissions will earn ZERO for the entire group
  affected.

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Goal of the team assignment

• Learning to develop a modular software system
  within a team following an object-oriented
  methodology
• we will use the Java Development Kit and Swing
  for group assignments
• Getting a feeling for the (management) problems
  in software development
• Software development is not just coding. A lot
  of planning and resource management goes into the
  creation of any reasonably-sized software
  product.
• Getting an idea of your own productivity
• Individuals must contribute positively to their
  group work

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Team assignment

• The software should be developed following basic
  software engineering principles
• processes code, test, design, review
• products story cards, test cases, test results,
  design documents, source code, review results,
  and productivity metrics

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Contents

• Organizational stuff
• Why software engineering?
• What is software engineering?

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What is Software?

• (Ideally) a structured collection of well
  documented and packaged series of instructions on
  data, that deliver computing power for driving
  practical processes and applications
• Application areas? Practically every walk of
  life health, education, transportation,
  government, military, , including driving
  hardware devices like cell phones, microwave
  ovens, etc.

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Characteristics of Software

• Developed in an evolving process during which
  all pieces are put together
• Is therefore easier to modify than hardware,
  without upsetting the use of the entire system
• Doesnt wear out in the same manner as hardware
• Could however be difficult to maintain, esp. in
  the presence of several defects

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Characteristics of Software

• Big RESPONSIBILITY for developers
• Consider lives at stake in hospital applications,
  for example
• or more lives in the aviation industry
• billions of dollars of investment
• Could be reused
• Strive for writing reusable modules
• components-based assembly

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Why Software Engineering?

• ...to get away from ad hoc and unpredictable
  software development towards a systematic,
  understood one...
• to provide an efficient process for creating
  high-quality programs

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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
• Inefficient defect detection / error recovery
• High cost and time pressure
• Shorter time to market
• Coordination problems within the projects
• Scarce resources
• These problems are chronic in that they have
  lasted for so long. These problems are caused by
  an interplay of misconceptions by management,
  customers, and developers alike

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Management myths

• State-of-the-art tools are the solution
• A fool with a tool is still a fool. Tools are
  often not used effectively
• Getting behind schedule resolved by hiring
  additional programmers
• adding people to a late software project makes
  it later, mostly due to training needs and
  learning curves

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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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Practitioners myths

• Once we write a program and get it to work, our
  job is done
• 60-80 of all effort after first delivery to
  customer
• 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) guide for
  future work, and good engineering discipline.

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The software crisis and a solution approach

• 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 an art
  rather than engineering discipline

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Practical disasters

• Y2K Lessons learned?
• European Space Agency Ariane 5
• Track control system failure results in self
  destruction
• NASA 1999
• Incorrect conversion from imperial?metric leads
  to loss of Mars satellite
• 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 still delivered late?

• Unrealistic deadlines forced from the outside
• Unfocused development too many unnecessary
  features, just in case
• Changed requirements not reflected in schedule
• Underestimation of effort
• Risks not considered
• Unforeseen technical human difficulties
• Miscommunication among project staff
• Management fails to see that the project falls
  behind schedule

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What can you do against unrealistic deadlines?

• You cannot change them
• You cannot refuse to do the work
• Perform detailed estimate
• Try to use incremental model
• define critical functionality
• postpone other functionality to later phases
• pair programming
• continuous integration
• Explain to the customer why you are not able to
  meet the deadline (using estimates based on the
  performance of past projects)

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Contents

• Organizational stuff
• Why software engineering?
• What is software engineering?

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Definition Software Engineering

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

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Three Ps
People
Processes
Products
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People, processes, products

• Processes
• planning
• testing
• estimating
• coordination
• management
• measuring
• designing
• coding
• pair programming
• continuous integration
• multiple iterations

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

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

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Summary

• Software engineering is the engineering-like
  development of a software system as the solution
  to an users problem applying the right
  techniques / methods / tools
• Software engineering is necessary for developing
  reliable complex software
• Software engineering techniques help to develop
  software in large teams

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Were Available!

• Questions?
• if you have any questions about contents of this
  lecture or other course-related issues, please
  come by during our office hours, or send us email
• Dr. Joshua MTW, 12-1pm, ICT 548
• joshuar_at_cpsc.ucalgary.ca
• Dr. Walker WF, 1-2pm, ICT 546
• rwalker_at_cpsc.ucalgary.ca