Need for logical analysis and thinking


  •  The Programming Process – Purpose

Understand the problem

  • Read the problem statement
  • Question users
  • Inputs required
  • Outputs required
  • Special formulas
  • Talk to users

Plan the logic

  • Visual Design Tools
  • Input record chart
  • Printer spacing chart
  • Hierarchy Chart
  • Flowchart
  • Verbal Design Tools
  • Narrative Description
  • Pseudocode

Code the program

  • Select an appropriate programming language
  • Convert flowchart and/or Pseudocode instructions into programming language statements

Test the program

  • Syntax errors
  • Runtime errors
  • Logic errors
  • Test Data Set

 Implement the program

  • Buy hardware
  • Publish software
  • Train users
  • Implementation Styles
  • Crash
  • Pilot
  • Phased
  • Dual

Maintain the program

  • Maintenance programmers
  • Legacy systems
  • Up to 85% of IT department budget

Problem solving with computers involves several steps:

  • Clearly define the problem.
  •  Analyze the problem and formulate a method to solve it (see also “validation”).
  •  Describe the solution in the form of an algorithm.
  •  Draw a flowchart of the algorithm.
  •  Write the computer program.
  •  Compile and run the program (debugging).
  •  Test the program (debugging) (see also “verification”).
  •  Interpretation of results.

 Verification and Validation

If the program has an important application, for example to calculate student grades or guide a rocket, then it is important to test the program to make sure it does what the programmer intends it to do and that it is actually a valid solution to the problem. The tests are commonly divided as follows: Verification


Verification verify that program does what you intended it to do; steps 7(8) above attempt to do this.
Validation does the program actual solve the original problem i.e. is it valid? This goes back to steps 1 and 2 – if you get these steps wrong then your program is not a valid solution.