| Direct | The old system is completely scrapped and the new one is implemented immediately |
| Phased | The new system is gradually implemented over a period of time (i.e. component by component) |
| Parallel | The old and new system are run simultaneously until the new system is ready for use. |
| Pilot (trial) | Instead of implementing the new system throughout the whole organisation, it is only implemented within one section or department. |
I believe cut-over refers to the implementation stage and the changeover/conversion methods. Changeover/conversion methods are ways of converting an old system to a new system. I'll list and briefly describe the ones you need to know for SD:
Direct The old system is completely scrapped and the new one is implemented immediately Phased The new system is gradually implemented over a period of time (i.e. component by component) Parallel The old and new system are run simultaneously until the new system is ready for use. Pilot (trial) Instead of implementing the new system throughout the whole organisation, it is only implemented within one section or department.