Evolution gives you two ways to buy from your suppliers, and choosing the right one keeps your job costs accurate and your stock under control. This page explains the difference between a purchase requisition and a purchase order, and helps you decide which to use.
The short version: a purchase requisition is an internal request to buy that is raised against a project, so the cost and the delivery are tracked against that project. A purchase order (PO) is the document you actually send to a supplier. Requisitions don't go to suppliers on their own — they are gathered up and imported onto purchase orders. Purchasing that isn't tied to a project (stock top-ups, workshop consumables) usually skips the requisition step and goes straight onto a purchase order.
When to Use Each
Use a requisition when what you're buying is for a specific project or customer and you want the cost and delivery tracked against that project.
- Job costing — the purchase is booked against the project so it shows in the project's costs and margin.
- Customer order tracking — you can see, from the project, exactly what has been requested, ordered, and received for that customer.
- Buying materials for a project — items pulled from the project's inventory, or raw materials exploded from a Bill of Materials.
- Approval before ordering — requisitions can be reviewed and approved before anyone commits to a supplier.
Go straight to a purchase order when the purchase is not tied to a particular project.
- Ordering for stock — replenishing inventory held on the shelf for general use.
- Workshop / general consumables — items used across many projects rather than costed to one.
- Overheads and supplies — anything you buy that isn't costed to a specific project.
- One-off supplier orders where you already know the vendor and the items and job costing and customer tracking is not needed
The Purchasing Workflow
Both paths converge on the same purchase order that goes to your supplier. Job-driven buying adds a few upstream steps (raise & approve a requisition) that keep everything linked back to the project; stock and consumable buying joins the flow at the purchase order.
route This is the same pipeline shown across the top of the purchasing screens: Project → Purchase Requisitions → Purchase Orders → Accounts Payable.
Where Things Live
| Screen | What it's for |
|---|---|
| Projects → Project Register → a project's Inventory tab | Where you raise requisitions for a project — see available vs. on-hand stock and request what's short. See Purchase Requisitions. |
| A project's Purchasing tab | Tracks that project's requisitions and their progress — requisition ID, PO, vendor, ETA and received status. |
| Purchasing → Requisitions | The register of all active purchase requisitions across every project, with their PO and ordered status. |
| Purchasing → Purchase Orders | Create purchase orders, import requisitions onto them, and send them to suppliers. See Purchase Orders. |
| Purchasing → Bin Re-order | Bulk-generate the requisitions and shop orders needed to top stock back up to its max. See Bin Re-order. |