The honest version of "does it integrate with my software." These are the systems this industry actually runs on, and what each one means for a build.
E2 Shop / JobBOSSShop ERP
The most common system of record in small and mid-size shops — quotes, jobs, routings, scheduling, time and job costing. Data access ranges from a documented interface to direct database reads depending on version and deployment, so this is the first thing to establish.
ProShop ERPShop ERP with quality built in
Notable because quality and document control live inside the system rather than beside it, which changes what a quality-facing agent has to do and usually reduces it.
Global Shop / EpicorShop ERP
The larger end. More capable, more structured, and more likely to involve a formal integration path.
Mastercam / Fusion 360 / SolidWorksCAM and CAD
Where the part is programmed. Mostly a source of files and metadata rather than an integration target, but revision level matters enormously and is worth reading rather than trusting.
Customer supplier portalsOrder intake
Larger customers push purchase orders, forecasts and drawing revisions through their own portals rather than sending them. No two are alike, and checking them is a daily manual chore in most shops.
QuickBooksAccounting
Where the money lives. The disagreement between quoted cost, actual job cost and what accounting says is the recurring reporting problem in this industry.
Quality documentationISO 9001 / AS9100
First article reports, material certifications, certificates of conformance, non-conformance records and corrective actions. Frequently a folder structure plus a spreadsheet, and audited annually against how well it is maintained.
Material suppliersPurchasing
Metal service centers and distributors quoting by email and phone. Pricing moves, quotes expire, and comparing three of them on the same cut list is a manual exercise done under time pressure.
Shop floor data collectionTime and production
Terminals or tablets capturing labor against operations. The quality of this data determines whether job costing means anything, and it is usually the weakest input in the shop.