How do we migrate open matters and historical spend when switching systems?

What are you actually moving?

More than the matter list. A litigation system accumulates the working state of every open case plus years of records that feed your reporting. Inventory all of it before any vendor conversation, because the migration scope you hand the new vendor determines the price, the timeline, and what you discover missing after the old system goes dark.

• Open matter files: parties, claims data, counsel assignments, budgets, deadlines, and case notes.
• Documents: pleadings, status reports, invoices as submitted, and every attachment tied to a matter.
• Historical spend: paid invoices, adjustments, appeal outcomes, and the timekeeper and rate records behind them.
• Reference data: your law firm panel, timekeeper rosters, approved rates, and the billing guidelines themselves.
• Closed matter history: outcomes and cycle times, the data your counsel performance and settlement analysis depend on.
• Configuration: guideline rules, approval workflows, and user roles, which migrate as rebuild work, not data transfer.

How does the migration actually run?

In phases, each with an exit gate. The sequence matters less than the discipline: nothing moves to the next phase until the current one validates against the source system. Migrations fail quietly, through unmapped fields and dropped documents that surface months later as a missing deadline or an unexplained spend gap, so the validation gates are the project.

1. Inventory and scope: catalog every data type, decide what migrates at full fidelity, what migrates as reporting data, and what stays archived.
2. Export and mapping: pull complete exports from the old system, then map every field to the new schema, normalizing task codes, timekeeper records, and firm identifiers along the way.
3. Trial load: migrate a sample of matters end to end, and have the people who work those files verify them against the source.
4. Validation at scale: record counts, financial reconciliation of migrated spend against AP totals, document counts per matter, and spot checks by the adjusters who know the files.
5. Pilot wave: one business unit or matter segment goes live and works real cases in the new system while the old one still runs.
6. Cutover and archive: remaining waves move, the old system goes read-only for an agreed retention period, and the final export is stored in an open format you control.

What fidelity does each data type need?

Open matters and historical spend have different jobs, so they justify different effort. An open matter must be workable the morning after cutover; a paid invoice from years ago must be countable and queryable, not workable. Spending full-fidelity migration effort on deep history is the classic scope mistake, and flattening open matters into summaries is the fatal one.

What goes wrong, and how do you keep leverage?

The failure modes are contractual before they are technical. The outgoing vendor controls your export, the incoming vendor controls the mapping, and your law firms carry the transition load of registering and resubmitting. Secure export rights and pricing in writing before announcing the switch, and make the new vendor's migration fee fixed against acceptance criteria you define.

• Export hostage: the outgoing vendor quotes a surprise fee or delivers a partial export. Counter: exercise your contractual export rights, in full, before you announce the switch.
• Mapping drift: fields with no home in the new schema get silently dropped. Counter: a signed mapping document with an explicit disposition for every source field.
• Invoice limbo: invoices submitted during the transition disappear between systems. Counter: a managed freeze window and a reconciled in-flight list owned by one named person.
• Firm fatigue: your panel re-registers, relearns, and resubmits. Counter: vendor-owned firm onboarding with a published schedule, communicated by you, not discovered by the firms.
• History amnesia: the analytics you relied on cannot be reproduced. Counter: reproducing your standard reports from migrated data is an acceptance criterion, before final payment.