Software Engineering Practice: A Generic View

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Software Engineering Practice A Generic View

• INTRODUCTION
• Practice is the collection of concepts ,
  principles, methods, and tools that a software
  engineer calls upon a daily basis.
• The Essence of Practice
• Understand the problem (Communication and
  analysis)
• Plan a solution (modeling and software design)
• Carry out the plan (code generation)
• Examine the result for accuracy (testing and
  quality assurance)

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Software Engineering Practice A Generic View

• UNDERSTANDING THE PROBLEM
• Who has a stake in the solution to the problem?
• What are the unknowns?
• Can the problems be compartmentalized?
• Can the problem be represented graphically?

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Software Engineering Practice A Generic View

• PLAN THE SOLUTION
• Have you seen similar problems before?
• Has a similar problem been solved?
• Can subproblems be defined?
• Can you represent a solution in a manner that
  leads to an effective implementation?

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Software Engineering Practice A Generic View

• CARRY OUT THE PLAN
• Does the solution conform?
• Is each component part of the solution probably
  correct?

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Software Engineering Practice A Generic View

• EXAMINE THE RESULT
• Is it possible to test each component part of the
  solution?
• Does the solution produce results that conform to
  the data, function, features, and behavior that
  are required?

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Software Engineering Practice A Generic View

• CORE PRINCIPLES
• The reason it all exists. Provide value to the
  user.
• KISS (Keep It Simple, Stupid!)
• Maintain the vision.
• What you rpoduce, someone else will have to
  consume. (implement knowing somone else will have
  to understand what you are doing)
• Be open to the future
• Plan ahead for reuse
• Think!

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Software Engineering Practice A Generic View

• COMMUNICATION PRACTICES
• Listen
• Prepare before you communicate
• Someone should facilitate the activity
• Face to Face communication is best
• Take notes and document decisions
• Strive for collaborations
• Stay focused
• If something is unclear, draw a picture
• Once you agree, move on. If you cant agree, move
  on.
• Negotiation must be win win.

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Software Engineering Practice A Generic View

• PLANNING PRACTICE
• Understand the scope
• Involve the customer in planning
• Recognize that planning is iterative
• Estimate based on what you know
• Consider the risk
• Be realistic.
• Define how you intend to ensure quality
• Describe how you intend to accommodate change.

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Software Engineering Practice A Generic View

• MODELING PRACTICE
• The domain must be understood
• Functions of the software must be defined
• Behavior of software must be represented
• The models that depict information, function, and
  behavior must be partitioned in a manner that
  uncovers detail in a layered fashion.
• Analysis task should move from essential
  information toward implementation detail.

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Software Engineering Practice A Generic View

• MODELING PRACTICE
• Design should be traceable.
• Consider the architecture of the system to be
  built.
• Design of data is as important as processing
  functions.
• Interfaces must be designed with
• User interfaces should be tuned to needs of the
  end-user.
• Component level design should be functionally
  independent Single mindedness
• Components should be loosely coupled
• Design representations should be easily
  understandable contradicts formal mathematical
• Design is iterative

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Software Engineering Practice A Generic View

• CODING PRINCIPLES
• PREPARATION
• Understand the problem
• Understand basic design principles and concepts
• Pick a programming language that meets the needs
  of the software being built
• Select a programming environment that makes you
  work easier
• Create sets of unit tests

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Software Engineering Practice A Generic View

• CODING PRINCIPLES
• CODING
• Select data structure that meet the needs of
  design
• Keep conditional logic as simple as possible
• Use meaningful variable names
• Follow local coding standards
• Write code that is self-documenting,
• Create a visual layout, i.e. indenting, better
  have a tool do it for you

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Software Engineering Practice A Generic View

• CODING PRINCIPLES
• VALIDATION
• Conduct a code walkthrough when appropriate
• Perform unit tests, correct errors you uncovered
• Refactor code

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Software Engineering Practice A Generic View

• TESTING PRINCIPLES
• Testing is a process of executing a program with
  the intent of finding an error
• A good test case is one that has a high
  probability of finding as-yet undiscovered error
• A successful test case is one that uncovers an
  as-yet undiscovered error.
• PRINCIPLES
• All tests should be traceable to customer
  requirements
• Test should be planned long before testing begins
• 80 of all errors uncovered during testing is
  traceable to 20 percent of all program components
• Testing should begin in the small and progress
  toward testing in the large
• Exhaustive testing is not possible.

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Software Engineering Practice A Generic View

• DEPLOYMENT PRINCIPLES
• Customer expectations for the software must be
  managed
• A complete delivery package should be assembled
  and tested.
• A support regime must be established before the
  software is delivered
• Appropriate instructional material must be
  provided to end-users.
• Buggy software should be fixed first, delivered
  later.