All inventory and shop supplies are ordered from one screen: shelf stock, oil by the case, brake clean, rags. No work order needed.
Go to Financial → Expenses → Shop & inventory order. From Inventory, the Order button on an item (or on an AI reorder suggestion) adds it here with a quantity filled in. Type one item per line with the quantity first (for example 2 cases 5W-30), pick the store under Order from, and press Have Mark order it.
Mark calls the store and asks for each item by name. No part number is needed. He checks they have it, gets the price and the order number.
Same rules as parts calls: closed stores are called when they open, the monthly call cap applies, the desk is texted if the call fails, and pressing twice never sends it twice.
If Mark's parts calls are off, the order is saved as a to-do. Call it in, then press Mark ordered and add the order number and cost.
Every placed order is logged as a supplies expense (store, order number, cost, date). It shows on Expenses and the Profit & Loss, never on a customer invoice.
Each shop order stays in the open list until you press Received.
Received adds each line to Inventory: it matches an item with the same name (or adds a new one) and raises the quantity. Untick Add to inventory for consumables you just use up. Unit cost is the order total split per unit unless you type it. Receiving twice never counts twice; Cancel & reverse takes the quantities back off.
Lines added to inventory are left out of overhead on the Profit & Loss (their cost counts when the part is used on a job). The expense entry itself keeps the full amount.