Upgrades
- Upgrades prolong product life
  - Insert more powerful computer into old product
  - Enhance and "maintain" software
  - Add additional sensors for more sophisticated control &
       diagnosis
  - Potential problems with compatibility
- Will all versions of other components work with newly upgraded
       component?
  - Will legacy software work with new hardware?
  - Can software really be ported to a new instruction
       set?
  - Different timing of different CPU implementations
  - Different hardware/compiler/assembler/linker bugs