SYSE.29:4.2 - Compare the transition choices

Consider continued support, narrowed support, coexistence, adaptation, replacement and retirement against the actual user result and constraints. Include the burden and risks of keeping the old provision as well as those of moving.

Identify where old/new configurations can coexist and where they cannot. Recover state correspondence, supported interfaces and the effect of new-only features. Returning an executable, restoring data and repairing forward are different operations. Use SYSE.34 for software persistent-data compatibility and restoration, and the appropriate domain Method for physical recovery.

Keep complete obtaining alternatives with SYSE.24 when the receiving provision itself is still a choice. Migration planning does not prove that the proposed replacement is the better arrangement.