The system of house-to-house billing has been running for a long time, and it will always be the day to change: old equipment is insured, the factory does not maintain it, and new platforms are more functional. But cutting is harder than building new ones because it is using running engines, and thousands of students are using them, and the process cannot break the net. We have done several cut guarantees, stepping on more pits than we built.
Checking the real assets of old systems first
The first thing before cutting is to make clear what's in the old system: how many accounts, what equipment has been tied, where there are room matching relationships, where historical bills exist, and whether there have been manual changes. Many schools run for years, data are already inconsistent with the original, moving directly without taking a count, and moving in the past is a mess. We suggest that we do a full export and check first, and pick up an anomaly.
The old and the new are more stable than the old.
The most dangerous cut is to close the old one at night and to turn off the entire building for a new platform if it has problems. We suggest that we start with the new one: the new one comes in first, runs real traffic, the old system keeps the bottom of the system, and which building is unstable. Parallels add short-term complexity, but give room for error. We have seen a school switch, the new platform has bugs, the whole dormitory is out of service until dawn. Parallelly, though trouble is the cheapest insurance available in cutting.
The account number and the bill map need to be reconciled once.
The fields of the old and new systems are often different, with the matching numbers of the Quarters, Rooms, Balances clearly map before moving. One is wrong. Students come to find that the balance is missing or the room is not right, and complaints explode. We suggest a map that takes out hundreds of items after running all the moves, checks them and confirms that the number, binding, and balances are right again. History bills should be filed in the original form, so that they can be checked, and not changed into new formats.
Switch window to least-at-a-student time
The best window is that the student does not have a peak in his dormitory after holiday or examination week. We suggest avoiding sensitive periods such as starting school, choosing classes, and testing, we advise that early notification of a short period may be volatile. To switch to a day when both sides are watching and immediately retreating from problems. A little fluctuation will be magnified by an accident, for example during the course of the selection. The cut window is made out of a game with the school calendar and not just a late night.
Old system save read-only period and offline
The old system is not in a hurry to dismantle before the new platform has stabilized. We suggest that a read-only filing period be maintained, for example three months, both to prevent withdrawal and to deal with queries and audits. If students question a historical deduction, the old data are still available during this period, it can be said. Confirming that there are no abnormalities in the billings, authentications, reconciliations, and then formally file them down. Many schools cut off the old system immediately, and as a result, they have to check their own accounts and find nothing.
We'll do a full-scale medical examination after the cut.
The cut is not the end; it takes a round of medical examinations: certification success rates, reconciliation differences, synchronous delays, bandwidth balances, full reading and comparison with pre-cutback baseline. We suggest that the checkups last for one or two weeks, looking at trends every day, and then looking at them immediately. The first two weeks after the cutting are the most vulnerable, the old problems may be unclean and the new configurations may fall out. It is only when the check checks are fixed that they will be cut to the end. Many accidents do not occur in the moment of the switch, the days that nobody sees after the switch.
Retrieval prep is better than cutting the plan.
The most feared thing about cutting is that the new platform is not going back. We suggest that we go back to the preset and the cut-off program, or even write back: which signals trigger a retreat, where to return, how the old system will be taken over, what students are supposed to send, clear and practice in parallel. Many teams only look at how to cut it, not try to cut it back, but do things at once.
You have to write a disk for cutting.
After cutting the proposal for a remix, which step is more consistent than expected and which step is useful, write it down next time. School network evolution is normal, this experience is the next one. The remunerative is not long, so writing key lessons into the transport manual is worth it.
The accommodation system cuts off the new platform from old equipment, essentially with an operating business engine. Stocking assets, old parallels, mapping clears, window selection, slotting old systems, post-cut medical examinations are all done in silence and students and teachers and students hardly feel changed.