Use Software Engineering Concepts to help design

• use-case diagrams,
• class diagrams,
• sequence diagrams.....
• Design Methodologies
• Patterns and Frameworks
• Always redesign ---refactoring =
  • The system should be as simple as possible.
  • Eliminate all duplicate code.
  • Adding code can make it more complex than necessary.
  • Refactor after adding code OR if it is easier to refactor before you add code, refactor before you add code.