Purchase Order Process: Step-by-Step Guide for Manufacturers

The purchase order process is one of the most important control flows in a manufacturing business.

When it works well, material arrives on time, suppliers understand requirements, stores knows what to expect, accounts can verify invoices, and production runs with fewer interruptions. When it works poorly, the same business gets shortages, duplicate purchases, wrong material, delayed approvals, payment disputes, and production stoppages.

The process itself is not complicated. The discipline is the difficult part.

A purchase order process must connect demand, approval, supplier communication, delivery tracking, material receipt, invoice verification, and reporting. If any step is skipped or handled informally, the cost usually appears later on the shop floor.

This guide explains the purchase order process step by step, why each stage matters, common mistakes, and how AICAN Optiwise helps manufacturing teams manage POs with better visibility.

Note: This article is for general business understanding only. Purchase, tax, accounting, contract, and compliance workflows may vary by company and law. Consult qualified professionals for specific advice.

What Is the Purchase Order Process?

The purchase order process is the series of steps a business follows to request, approve, order, receive, verify, and close purchases.

A typical process includes:

1. identifying requirement
2. raising purchase requisition
3. checking stock and budget
4. selecting supplier
5. approving purchase
6. issuing purchase order
7. supplier acknowledgement
8. delivery follow-up
9. goods receipt and inspection
10. invoice matching
11. payment processing
12. PO closure

The exact flow may vary, but every manufacturer needs a clear version of it.

Step 1: Identify Purchase Requirement

The process starts when a department needs material, components, tools, consumables, services, spare parts, or packaging.

In manufacturing, requirements often come from:

• production planning
• sales orders
• stock reorder levels
• maintenance needs
• quality department
• projects
• administration

A good requirement should include item, quantity, specification, required date, department, and reason.

Step 2: Check Existing Stock

Before buying, the team should check current stock, reserved stock, pending purchase orders, and expected consumption.

This step prevents unnecessary buying. Many businesses over-purchase because teams raise requests without checking inventory properly.

Step 3: Raise Purchase Requisition

A purchase requisition is an internal request to buy. It is not sent to the supplier. It helps the business review whether the purchase is needed and approved.

The requisition should mention:

• item code and description
• quantity
• required date
• department or cost centre
• purpose
• priority
• suggested supplier, if any

Step 4: Review and Approve

The requisition should be reviewed based on need, stock availability, budget, urgency, and approval limits.

Approval rules reduce unauthorized purchases and cost leakage. For example, low-value consumables may need department approval, while high-value machinery may need director approval.

Step 5: Select Supplier and Compare Terms

The purchase team selects supplier based on price, quality, delivery record, payment terms, capacity, and reliability.

For important purchases, quotation comparison should include total landed cost, not just unit price. Freight, taxes, packing, delivery time, warranty, and quality history all matter.

Step 6: Create and Issue Purchase Order

After approval, the purchase order is created and sent to the supplier.

The PO should include:

• PO number and date
• supplier details
• buyer details
• item description and specifications
• quantity and unit
• price and taxes
• delivery date
• delivery location
• payment terms
• quality requirements
• terms and conditions
• authorized approval

This document becomes the main reference for supplier delivery and invoice verification.

Step 7: Supplier Acknowledgement

The supplier should confirm acceptance of the PO, delivery date, price, and terms. Without acknowledgement, the buyer may assume the order is accepted while the supplier has not planned it.

Supplier acknowledgement is especially important for urgent, custom, or high-value purchases.

Step 8: Track Delivery

Purchase follow-up should begin before the due date, not after material is late.

Pending PO tracking helps answer:

• what is due this week?
• which supplier is delayed?
• which material affects production?
• which PO is partially delivered?
• which delivery needs escalation?

Step 9: Receive Goods

When material arrives, stores should receive it against the PO. Quantity, item, packaging, and documents should be checked.

The goods receipt note, or GRN, records what was actually received.

Step 10: Inspect Quality

For manufacturing materials, quality inspection may be required. The team may check grade, dimension, certificate, test report, tolerance, packaging, or functional performance.

Rejected or short material should be recorded properly.

Step 11: Match Invoice

The supplier invoice should be matched with the PO and goods receipt. This is often called three-way matching.

It prevents payment for wrong quantity, wrong rate, rejected material, duplicate invoices, or unapproved charges.

Step 12: Close Purchase Order

Once the ordered quantity is received, inspected, invoiced, and settled according to process, the PO can be closed.

Open POs should be reviewed regularly. Old open POs create confusion in inventory and purchase planning.

Common Purchase Order Process Mistakes

Skipping Purchase Requisition

When users directly ask suppliers without internal approval, purchase control becomes weak.

Poor Specifications

Vague item descriptions lead to wrong material.

No Supplier Acknowledgement

Without acknowledgement, the buyer has no confirmation that the supplier accepted the order.

Weak Pending PO Follow-Up

Following up after the due date is often too late for production.

No PO-GRN-Invoice Matching

Paying invoices without matching can lead to overpayment and accounting errors.

Closing Without Review

POs should not remain open forever. They should be closed or cancelled with proper reason.

How ERP Improves the Purchase Order Process

A manufacturing ERP creates a connected purchase order workflow.

It helps teams:

• raise requisitions from production or stock needs
• check available inventory
• route approvals
• create POs with standard formats
• track supplier delivery
• record goods receipt
• update inventory
• match invoices
• monitor open POs
• review purchase reports

Optiwise by AICAN supports this connected thinking for manufacturing SMEs. It helps purchase, stores, production, accounts, and management work from cleaner shared data.

Best Practices

Use standard item master data.

Define approval limits clearly.

Mention specifications in detail.

Track supplier acknowledgements.

Review pending POs frequently.

Match PO, GRN, and invoice before payment.

Close old POs after review.

Analyze supplier performance regularly.

Founder’s Note

At AICAN, we see the purchase order process as a chain of small controls. None of them look dramatic alone, but together they protect production, cash flow, and customer delivery.

AICAN Optiwise helps manufacturers bring that control into daily work. When requisitions, approvals, purchase orders, goods receipt, and reporting are connected, the business stops depending on memory and starts operating with evidence.

FAQs

What is the purchase order process?

It is the workflow used to request, approve, issue, track, receive, verify, and close purchases.

What are the main steps in a PO process?

The main steps are requirement identification, stock check, requisition, approval, supplier selection, PO issue, delivery tracking, goods receipt, invoice matching, payment, and closure.

Why is purchase order approval important?

Approval prevents unauthorized buying, improves budget control, and creates accountability before the business commits money.

What is three-way matching in the PO process?

Three-way matching compares the purchase order, goods receipt, and supplier invoice before payment.

How does Optiwise improve the PO process?

Optiwise by AICAN helps connect requisitions, purchase orders, inventory, goods receipt, supplier follow-up, invoice checks, and reporting.