• build many different models; choose best
• simulate, using program: use loops

Build Dog Lot.                     x    |
Put fence next to wall.         ********|
Have one roll of fencing.       *       |
                                *       |
                             y  *       |
                                *       |
                                *       |
                                *       |
                                ********|
                                   x    |

• Robustness
• Testing
• Documentation
• Customer Support
• Training
• Follow-on products

• The perfect program that crashed
• The rotten program that kept on going

• Defining the Product
• Developing the Program Specification
• Designing the System Structure
• Coding the System (small part!)
• Testing the Code
• Revision
• Documentation
• Delivery and Training
• Maintenance and Upgrade

• Proofs
  • What is a proof?
  • Formal definition of specs
  • Formal definition languages
• Very hard
• Changing Specs
• Where useful?

• Comments on Comments
  • Program Header
  • Block Header
  • Line Comments
  • Procedure Specs
  • Variable Descriptions
• Manuals
  • User Manual
  • Software Logic/Technical Manual
• On-line documentation

• Testing Plan
• Test teams
• Seeding

• The "Committee"
• Communication
• Interaction
  • training
• Creator Independence

• Chief Programmer Team
• Modeled after surgical team
• Productivity varies by factor of 100 or even 1000
• Design vs Coding
• Have assistants do clerical stuff
• Librarian

• Oldest: Revision Control System
• Program that "used to work"