The logical design provides the user's view of the system, while physical design specifies the actual way the system will be implemented. Logical design specifies the desired logical assembly of the system relative to what it will do and why, while physical design specifies how to physically implement the logical design.
System Analysis and Design Documentation:
• Designer/developer documentation which provides a "bird's-eye" view of the system to allow the project team to track the development of the project. This documentation becomes a permanent record for the completed system. All facts gathered and recorded become part of the development.
Three Alternative Perspectives that Exist for Each of the Three Alternative Solutions:
• The pessimistic (conservative) solution.
• The most likely (middle of the road) solution.
• The optimistic (liberal) solution.
These solutions suggest answers to the "what if" questions that assume either:
• The worst possible outcome.
• The most likely outcome.
• The best possible outcome.