| Common improvement and installed reliance | Whether to extend, adapt, coexist, migrate or retain the current arrangement. |
| Technical compatibility and useful continuity | Which meanings, workflows and support must survive beyond an interface test. |
| Timely retirement and continuing obligations | What can end, under whose authority and after which receiving result is available. |
| Migration and ordinary service | Which changes can share scarce performers and operating windows. |
| A simpler future family and a costly transition | Whether the benefit survives the full support and migration burden. |