Every PACS vendor will tell you their migration process is smooth. Every systems integrator will tell you they've "done this hundreds of times." Some of that is even true. But the questions that actually predict whether your go-live weekend is calm or chaotic rarely come up in the sales pitch.
Ask who's actually doing the work
Large integrators often sell you a senior architect in the proposal meeting and staff the actual migration with someone two years out of school. Ask, explicitly, who will be hands-on during cutover — by name, not by title.
Ask about cross-vendor DICOM experience, specifically
A consultant who has only ever migrated between two systems from the same vendor family hasn't seen the failure modes that show up when transfer syntaxes, private tags, and association negotiation behave differently across brands. Ask for a specific example of a cross-vendor migration they've run, and what broke.
Ask what the rollback plan looks like
If the answer is vague, that's the red flag. A consultant who has actually run migrations will have a concrete, tested rollback procedure — not "we'll figure it out if something goes wrong."
Ask how they handle legacy studies and edge-case data
Old studies with malformed headers, orphaned series, and non-standard modality data are where migrations quietly lose data. A consultant who hasn't been burned by this before won't have a plan for it.
What independence buys you
Consultants tied to a specific PACS vendor have an incentive to steer your architecture toward that vendor's roadmap, whether or not it's the right fit. Independent consultants have no such conflict — the plan is built around your imaging volume, staffing, and compliance needs, not a license renewal.