A project involves four roles with these rules:

1. Work must proceed in sequence: A → B → C → D

2. Each role must notify the next role upon completion

3. If any role changes scope, all downstream roles must be informed immediately

4. If no notification is received, roles must not assume completion

  • Role B completes work and expands scope slightly.

  • Role C proceeds without being notified.

  • Role D waits for confirmation.