Changing ERP: what to migrate and where to keep historical data

Where five years of work will go

Move the data you need for ongoing work: active customer and supplier records, outstanding balances, open orders, stock and system setup data. Keep the history in the old system, read-only, or an exported archive, while meeting the applicable document preservation requirements.

“I don’t want to lose five years of work.”

It is a reasonable concern. A paid invoice needs to remain accessible; an outstanding order needs to carry on through the new system.

Keeping records and using data are different requirements. Italian law requires you to retain certain documents, not to import them all into your current software. For each group of records, decide where you will keep it, how you will access it and who will be responsible.

You can also organise old and new information into a knowledge base that lets you ask AI questions, much as you would ask a colleague.

Retention and daily work need separate decisions

Your new system needs accurate operational data so you can collect payments, fulfil orders and check stock.

Retained documents let you establish what happened: an invoice issued, an accounting entry, a purchase. You must be able to read and retrieve them throughout the required period, even when you no longer need them every day.

Guidelines from AgID, Italy's digital agency, require the preservation system to be at least logically separate from the document management system. You can use the same provider, but preservation must remain distinct from document management. Finding a document in your ERP does not, by itself, prove that it meets preservation requirements.

Decide which data you need for daily work and how to preserve the documents you must retain.

What to bring into the new system

Ask: will you need this data to work after the changeover? For every yes, identify who will use it and for what.

Active customer and supplier records. Start with those you have traded with over the last two or three years. Check exceptions too: an older account may still have an open order or balance. Check VAT numbers, payment terms and e-invoicing recipient codes, which route invoices through Italy's invoicing system. Find duplicates and decide which record to keep. Allow for this cleanup in the project.

Outstanding receivables and payables. Transfer each outstanding item with its remaining balance, date, due date and document reference. A total per customer or supplier will not let you manage individual payment deadlines. Agree any other opening account balances with whoever handles your books.

Open documents. Unfulfilled orders, active quotes and purchase orders awaiting delivery all represent work still to do. Make sure the new system shows what remains outstanding, including partial deliveries.

Stock at changeover. Bring across quantities by item and location, with values agreed by your stock and accounting teams. The opening position and your checks must refer to the same changeover date.

Product, manufacturing and accounting setup. Items, bills of materials, manufacturing routings and the chart of accounts, as relevant to your business. Try them in the new system's processes. Having all the rows in place does not mean you can use them.

History for comparisons. If a year of sales by customer and product, or two at most, gives you what you need, consider a separate report. Import individual transactions only if your comparisons require that detail.

What can stay out

Entries from closed accounting years. Do not import these by default. Use the archive for reference or checks. Agree with your accountant which information you do need for continuity in the accounts.

Historical stock movements. The position at changeover may be enough to establish your opening quantities. Before excluding earlier movements, check whether you need them for returns, warranties or traceability. If you do, decide where you will look them up.

Records no longer in use. You can leave inactive customers, suppliers that have ceased trading and discontinued products out of your working lists. Keep enough context to understand historical documents. Excluding a record from migration does not mean erasing every trace of it.

Closed and paid documents. Settled invoices from previous years can stay in the preservation archive. Decide how you will retrieve them when you need them during your work.

Import data with a defined purpose; give everything else a home and a way to access it. If in doubt, ask whoever uses it.

Where to keep the history

You can combine these arrangements. Keep access for reference distinct from legally compliant preservation.

The old system, read-only. If the licence allows it, you can consult historical records in their original context. Record who maintains it, who has access and for how long. Test it by opening and exporting documents.

An archive of exported documents and data. PDFs, XML files and CSV files for tabular data can give you reference access. Organise them so you can find a document by customer, date and number. Check that the export contains what you need and that you can open the files without the old system. The format alone does not make an archive complete or usable.

Legally compliant electronic preservation. This is mandatory for Italian electronic invoices. If you use the Italian Revenue Agency's service in its Fatture e Corrispettivi portal, check which invoices have actually been accepted for preservation. Passing through SdI, Italy's invoice exchange system, is not confirmation of preservation. With a private provider, check the contract and preservation manual for access arrangements and what happens when you change providers.

Keeping XML copies on a drive does not meet preservation requirements. The process under the Ministerial Decree of 17 June 2014 includes specific requirements, such as a record of the date and time on the archival package with legal effect against third parties. It also requires metadata and the ability to produce documents under the applicable rules.

The old system and exported folders do not, on their own, replace the required preservation process.

History you can ask questions of

When finding information means remembering menus, codes and filters, it is easy to put off a search or ask someone who knows the software better. A new system can make that work feel even less familiar. AI can change that relationship, provided you organise the information into a knowledge base it can work with.

A knowledge base brings together your exported archive, PDFs, XML files, spreadsheets, written procedures and data from the new system. Describe what each source contains, the customer, product or period it concerns, and where it came from. That is what makes it more than a folder.

You can then ask: “What payment terms have we had with this customer over the last three years?” or “Where’s the invoice for that return?” AI can answer in plain language and point you to the document behind the answer, even when the sources use different formats.

You can add information by typing or speaking naturally, too: a customer note, the outcome of a check, an exception to a procedure. AI can associate it with the relevant records, ready for the person responsible to review.

A typical case. An owner-managed business is acquired by a multinational and must move to the group's ERP. People's work changes, as do the processes and the way the systems organise data. Meanwhile, the history still needs to be available.

If the two knowledge bases remain separate but AI can search both, you can ask for information without knowing which system holds it. That can help if you struggled with the old software and feel reluctant to use the new system.

Three cautions apply. A knowledge base does not replace legally compliant preservation. Check AI answers against the documents they cite, especially before a payment, dispute or inspection. Keep the source systems' access permissions in place: asking a question must not reveal data you were not allowed to see before.

The deadlines that matter

Read retention periods alongside tax assessment deadlines. An assessment deadline does not authorise you to delete documents you must still keep.

Ten years. Article 2220 of the Italian Civil Code requires you to keep accounting records for ten years from the last entry. You must retain invoices, letters and telegrams received, and copies of those sent, for the same period.

The fifth year, or the seventh. Article 43 of Presidential Decree 600/1973 requires a tax assessment to be served by 31 December of the fifth year following the year you filed the return. If the return was omitted or is void, the deadline is 31 December of the seventh year following the year it should have been filed. These are assessment deadlines, not alternative retention periods.

Until assessments are finalised. Article 22 of the same decree requires you to retain accounting records until assessments for the relevant tax period are finalised, even beyond the civil-law retention period. Check the status of any assessments with your accountant before deleting documents.

At least fifteen days to produce documents. For a formal request to produce documents, Article 32 allows no less than fifteen days from notification. Do not count on that time to rebuild your archive. Establish how you will find and retrieve records beforehand.

These duties also cover documents you leave out of the migration. Changing systems neither restarts nor interrupts the statutory periods.

How to check the migration

An import confirms the data has loaded. Before accepting the migration, check that it supports your work correctly.

1. Reconcile the balances. Compare receivables and payables in both systems as at the same date. Totals must match to the cent; check individual outstanding items too. Trace and explain every difference before accepting the opening balances.

2. Compare record counts. Compare the customer and supplier records, products and outstanding items selected for migration with those imported. Document agreed exclusions and merged records. A difference may be correct, but you need to explain it.

3. Check a sample manually. Choose ten real customers covering different situations: a large customer, a small one, one with an open dispute and one overseas. Check their details, balance and latest document reference. Also try retrieving an archived document excluded from migration.

4. Run a complete process using a real case. Before going live, work through an order, delivery, invoice and payment in a test environment. Involve the people who do the work so they can check the data and each step.

Adapt these checks to your business processes. Record the results and who performed them: a successful import is only the start.

Mistakes to avoid

Importing everything “to be safe”. Every set of imported data needs checking. Establish its purpose first. Find duplicates and outdated information so they do not follow you into the new system.

Leaving nobody responsible for the history. “We’re keeping the old software running” does not tell you whom to ask when a document is missing. Assign someone responsibility for access, maintenance and checking that documents remain available, with clear deadlines.

Bringing in the accountant after the import. Agree the changeover date, opening balances and information needed to close the books beforehand. Involve the people who handle administration and stock each day: they will be working with the data.

What to decide before the switch

List the old system's data and documents. For each group, record what you will import, where the history will stay, who will be responsible and how you will check that you can retrieve it.

If you want to ask AI about historical records, add three lines: what each group contains, what it relates to and who can see it. The same list becomes the foundation of your knowledge base.

You can then locate those five years of work, consult them and identify what you will use in the new system.

If you are unsure about some records, get in touch and explain how you need to use them. Test your list with the system's future users: choose an outstanding order and a paid invoice, then check where and how to find them.

Redazione Gitogi