SDD

• Development methodologies

  Iterative and agile
• Client Interaction

  Iterative - Client involvment at the start and end, specification is fixed

  Agile - Client involvment and feeback throughout development, goals can change throughout
• Teamwork


  Iterative - Teams work independently with minimal communication

  Agile - Teams collaborate with frequent meetings
• Documentation

  Iterative - Detailed specification created at the beginning

  Agile - Reduced documentation with small cycles of implementing, testing and evaluating
• Measuring progress

  Iterative - Strict plan with timescales set in the beginning

  Agile - Broken down into short development goals
• Adaptive vs Predictive


  Iterative - Plans in advance for known risks found in early phase analysis

  Agile - Makes changes as issues are encountered
• Testing

  Iterative - Tesing occurs when implementation is complete

  Agile - Testing occurs alongside implementation
• Purpose 


  A general description of the purpose of the software
• Scope


  A list of the deliverables that the project will hand over to the client
• Boundaries


  The limits that help to define what is in the project and what is not
• Functional requirements


  The features and functions that must be delivered by the system in terms of inputs, processes and outputs.
• Creating substrings


  use slice
• Converting to ASCII


  ord()
• Convert to character 


  chr()
• Convert to integer


  int()
• Find modulous


  %
• Standard Algorithims 


  • Input validation
  • Linear search
  • Finding maximum
  • Finding minimum
  • Counting occurences
• Formal parameters stand in place for the value that will be passed in
• Actual parameters are the actual values passed into a subroutine
• A global variable means it is accessible in every sub-routine
• Local variables only exist in the subroutine in which they are declare
• Testing should be both systematic and comprehensive
• Testing shows if a program meets the functional requirements
• Types of test data

  Normal, Extreme, Exceptional
• Dry runs manually step through each line of code and not the values of the variables
• Breakpoints and watch points with stop execution and watch specific lines or variables
• Benifits of modularity 


  • Less code has to be written and can be reused
  • Teams can work on seperate parts of the code
  • Code is easier to read and debug
• Fitness for purpose establishes whether or not the software fulfils all the functional and user requirements
• Efficiency


  • Suitable Data Types
  • Conditional or Fixed Loops
  • Arrays
  • Nested Selection Statements
  • Procedures/functions with parameter passing
• Usability


  Accsessible, customisable and consistent user interface
• Maintainability


  • Modularity
  • Meaningful variable names
  • Indentation
  • Comments
  • Whitespace
• Robustness


  • Input validation
  • try...except