How to use RigXy

A Part is anything you stock or buy to keep an asset running — an oil filter, a brake pad, a coolant gallon, a windshield wiper. Each Part is master data: one row per SKU, with name, manufacturer, part number, unit of measure, and an optional default vendor.

Stock lives per-Location. The same brake-pad SKU can have 12 units at the Oakland yard and 0 at the LA yard — those are two PartStock rows. Adding a Part does NOT create stock; you raise stock by recording a purchase-in transaction at a specific location.

Every movement is journalled in Part Transactions. Five types: PURCHASE_IN (you bought parts from a vendor), WO_OUT (a work order consumed parts), RETURN_TO_VENDOR (you sent parts back), TRANSFER (moved stock between two locations), ADJUSTMENT (audit correction with a reason). The ledger is append-only — even reversals create a new offsetting transaction, so the audit trail is complete.

Low Stock is a derived view: any (Part × Location) where on-hand quantity drops below the per-Part `min_stock_threshold`. Use it as your reorder dashboard — one click to start a PURCHASE_IN against the default vendor.

A Vendor is a parts supplier — the company you place orders with and receive invoices from. This is master data: one row per supplier, edited only by COMPANY_ADMIN. There is no DELETE — retire a vendor by flipping `status` to INACTIVE; historical PURCHASE_IN transactions keep showing the vendor name forever.

Vendors are distinct from Service Shops. Vendors sell you the parts you install yourself; Service Shops perform labor for you. Some companies are both (a brake shop that also sells you pads over the counter) — in that case create one record in each module under the same name.

On the Add-Part / Purchase-In modal, the Vendor dropdown auto-completes against this list. If a mechanic types a brand-new vendor name that doesn't exist, the system creates the Vendor record automatically (`find_or_create_by_name`) so the mechanic never has to context-switch — you can fill in phone / email / address later from the Vendors page.

The optional Business hours, Will-call phone, and Fax fields are there because real fleet operators care about them. Weekend / Friday hours often differ from weekday hours — keep them all in one block. Will-call is the dedicated parts-pickup line that bypasses the main switchboard. Fax is still alive at older parts houses and is the only way to send a PO at some shops.

A Service Shop is a third-party repair facility you dispatch external work to — an off-site mechanic, a tire shop, a transmission specialist, a body shop. When a work order is `repair_location_kind = EXTERNAL_SHOP`, the form requires you to pick a Service Shop (or type a name to create one inline, same find-or-create pattern as Vendors).

Service Shops are NOT Vendors. A Vendor sells you parts you install; a Service Shop performs labor for you. The accounting trail is different (invoice line items vs parts inventory), the audit story is different (who fixed it vs what was installed), and the operational flows are different (Service Shops show up on WO dispatch, Vendors show up on PURCHASE_IN).

Each Service Shop carries contact info (name, phone, email, address, notes) and a status flag. Same lifecycle as Vendors: COMPANY_ADMIN-only writes, no DELETE, status flip to retire. The shop name lives on every WO + MR that dispatched to them, so you always have a complete history of "who did what on this truck".