CS 3302 Software Engineering

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CS 3302Software Engineering

• Colin Potts
• Georgia Tech,
• College of Computing

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What is Software Engineering?

• An Exercise List all the ways in which
• Building a tinkertoy car for fun is different
  from designing a new automobile
• Building a treehouse is different from the
  architecture of a high-rise office building
• Having some friends round for a party is
  different from organizing the Olympic Games
• So, how might software engineering be different
  from writing a 50-line Java applet?

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Software Engineering CS course projects

• "instructors" are professional customers or
  company's marketing staff.
• "assignments" are ill-defined and constantly
  changing.
• responsible for acquiring tools you need.
• professional responsibilities.
• have to be able to work in teams.
• large project that is far too big to understand
  as a whole.
• products may last for years or even decades.
• have to understand the problem domain in which
  software will work.

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What You Will Learn

• Understanding, clarifying and documenting the
  requirements for a customer.
• Planning and managing a project, including effort
  estimation, risk analysis, contingency planning,
  and re-planning if the schedule is not met.
• Designing a software system at the architectural
  and detailed levels.
• Communicating and justifying design decisions.
• Reviewing and testing designs and
  implementations.

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1. Software Engineering Principles Software
engineering programming. Software lifecycle
models. Complexity management CASE.
Design abstraction, OO devt. SE.
Testing2.Software Engineering Practice
Customer requirements Software
specification Object-oriented analysis
Project planning mgt. Software design.
Translating designs into running code.
Integration Evolution of software.
Course Details

• See Web page for (currently tentative) schedule,
  information about the textbook, etc.

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Software Engineering

• What does designing a big software system most
  resemble?
• Engineering, architecture planning
• Designing a car? Constructing a high-rise
  building? Planning a major event?
• Softwares essence
• Conceptual complexity
• what is complexity? Why conceptual?
• Softness
• how are software maintenance and TV maintenance
  different?
• Invisibility
• just what is software anyway? And how can it be
  engineered?

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Cost of SE phases
Can this much effort really be maintenance?
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Software Evolution

• All engineering artifacts exist in an environment
  for external purposes, e.g
• bridges / cars transportation
• sound equipment performing arts
• But software design usually involves work /
  organization redesign
• if software codified intent, then new software
  shapes intents is focus of organizational
  change
• Software engineers are often unwitting change
  agents their systems are treated with suspicion
• Which means that software evolves gradually as
  the environment/mission evolves

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Types of Software Maintenance

• Corrective maintenance
• Fixing defects (bugs)
• I.e. correcting design flaws
• Perfective maintenance
• Improving the product (enhancements)
• Because of new requirements
• Or misunderstood requirement
• Because of new technological opportunities
• E.g. increased distribution of a centralized IS
  onto client-server architecture
• Reflecting changes in the environment
• Changes to tax laws, changes to ways of working,
  etc.
• Or unanticipated changes

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Phases of Software Development(SE as planned
evolution testing of software, not just
developing it)

• Traditional phases of software generation
• Requirements
• Specification
• Design
• Implementation
• Integration

• Evolution
• Development and redevelopment throughout process,
  not a phase at the end
• Testing
• Reviewing and assessing throughout process, not a
  phase near the end