How to Move to a New System Without Losing Your Data
In short
A safe data migration has four stages: audit what you have, clean it before it moves, run a test migration you verify yourself, then move for real with the old system still available as a fallback. Most migrations that go wrong skipped the cleaning stage or had no way back.
Changing systems is one of the few technology decisions where the downside is permanent. A website that looks wrong can be fixed next week. Customer records that were silently dropped during a migration are often gone for good. Here is what the process should look like, and what to ask before anyone starts.
What data migration actually involves
In plain terms: taking the information out of your old system, reshaping it so it fits the new one, and putting it in without losing anything. The reshaping is the difficult part. Two systems almost never store information the same way, so decisions have to be made about what maps to what, and what to do with anything that has no equivalent.
Those decisions are business decisions rather than technical ones, which is why a migration that happens without your involvement tends to produce surprises.
The four stages
1. Audit
Find out what you actually have. This routinely uncovers duplicate customers, records with missing fields, and data nobody has used in years. It is also where you decide what is worth bringing across at all, since migrating dead data costs money and clutters the new system.
2. Clean
Fix the problems before the move, not after. Deduplicate, standardise formats, fill or remove empty fields. This is the stage people skip when they are in a hurry, and it is the stage that causes the most damage when skipped, because a mess moved into a new system is still a mess.
3. Test migration
Run the whole migration into a copy of the new system and check it properly. Not a spot check: pick real records you know well and confirm every field arrived correctly. This is your opportunity to catch mapping mistakes while they are still cheap to fix.
4. The real move
Done in a planned window, with a full backup taken first and the old system left running until you have confirmed the new one is right. You should never be in a position where the only copy of your data is in a system you have not yet verified.
What actually goes wrong
- Relationships between records break, so invoices lose their customers
- Dates shift because two systems assume different formats
- Special characters in names and addresses become unreadable
- Attachments and documents are left behind entirely
- History is truncated, so only recent records come across
- Nobody checks the result until weeks later, when the old system is gone
Every one of these is preventable with a test migration that someone actually inspects.
Questions to ask before you commit
- What is the rollback plan if the migration fails?
- Will I see a test migration before the real one?
- Who decides what happens to data with no equivalent in the new system?
- Are attachments and documents included, or only records?
- How will we verify that everything arrived correctly?
If a supplier cannot explain the rollback plan in one sentence, they do not have one.
The honest summary
Migration is not technically glamorous and it is routinely underestimated in both time and cost. Budget for the cleaning stage, insist on a test run you personally check, and keep the old system until you are certain. Done carefully it is unremarkable, which is exactly what you want it to be.
Questions
Related questions
What is data migration?
Data migration is moving your information from one system to another, for example from spreadsheets into a CRM, or from an old platform to a replacement. It involves extracting the data, reshaping it to fit the new system, and loading it in without losing history or breaking relationships between records.
How much does data migration cost?
Most small business migrations cost between $2,000 and $12,000. The price is driven by how messy the source data is and how many systems are involved, not by how many records you have. Fifty thousand clean records are cheaper to move than five thousand inconsistent ones.
How long does a data migration take?
Two to four weeks is typical. The move itself usually takes hours; the time goes into auditing, cleaning and testing beforehand. Rushing those stages is the most common cause of a migration that has to be redone.
Will my business have to stop during the migration?
It should not. A well-planned migration runs the real move in a quiet window, often overnight or at a weekend, with the old system kept available until you have confirmed the new one is correct.
What happens if something goes wrong?
Nothing should be irreversible. Before the real migration there should be a full backup of the source data and a documented way to roll back. If your supplier cannot explain the rollback plan, that is a serious warning sign.