Timing and Versions
The Enterprise Specification has the same lifetime as the system. If policies change, they affect the running system, often on precise time-scales.
- a pricing policy, or a tax structure may need to be introduced on a specific date;
- other development and maintenance will need to be carried out in parallel;
- recovery and back tracking are needed;
- need preparatory changes and dummy running;
- need flexible build process and version control.