The vendor does not answer email, the server is still in the room, and nobody dares shut it down. This is not a reskin. It is asset preservation plus cutover. Extend often has no construction surface; lean rebuild. How to decide: see Should you extend a legacy OA or rebuild it?.
- Preserve. Admin accounts, database backups, attachment disks, SSL, and the domain. If the account stops, images and text can vanish together.
- In-flight tickets. Open leave, expenses, seals, and contract reviews must continue in the new system or be closed by hand and reopened.
- Read-only history. Audit samples and labor disputes must still open old attachments. How to migrate: see How to migrate data from a legacy OA.
- Rebuild permissions. Do not copy name-ticked grants. Redraw roles so transfers do not break; see How to-dos and permissions survive when a manager leaves.
- Dual-run window. Write a hard day count. On expiry, close the old write entry; search can stay. A dual-run that lasts too long is messier than the vanished vendor.
- Notice channel. When the old SMS gateway or mail webhook stops, to-dos go silent. Test WeCom or email before cutover; see Is WeCom enough, or do you still need your own back office?.
Do not shut the old site on a Friday afternoon. Do not cut over during tenders, payroll, or seal peaks. Make the old site read-only first; preview the new site, then cut.
If you cannot get source, restore the work—not the menu
List what people actually do each week. Do not treat screenshots of the old nav as the brief. Empty packaged modules do not need to move; see A packaged OA nobody uses is almost as bad as having none. Ask before you start: licenses, who owns the server, and whether the database can be exported legally. Avoid a live new system whose old library is stuck in a contract fight.
DaXi replacement projects archive read-only and close in-flight tickets before new to-dos. Go to the Management systems service page and say whether you can enter the server room and whether you can export. Engineering order: see From brief to launch: how a management system is built. Talk cost as preservation plus phase-one flows; see What an OA / management system costs, and how long it takes. A vanished vendor is not a reason to gamble on “shut the old site first.”