What is an order management system?

The purchase order went out on Tuesday. By Thursday, the wrong quantity arrived from the wrong supplier location. Your accounts payable team had already matched the invoice. Now someone has to unpick the payment, chase the supplier and explain to the department head why their project is delayed.

For procurement teams managing growing order volumes, issues like this create unnecessary cost, delays and frustration. The challenge is rarely a single mistake. It is a lack of visibility into what happens after an order is placed.

Most organisations can see what they spend. Far fewer can see how customer orders, purchase orders, approvals, inventory, delivery and returns move through the wider process. When that information sits across multiple systems, errors become harder to spot and harder to fix.

This guide explains what an order management system is, how it works and what procurement leaders should evaluate before choosing an order management solution.

What is an order management system?

An order management system (OMS) is software that manages the full lifecycle of an order, from the moment it is placed to delivery, payment and returns. It coordinates the information and actions across every stage of that journey: capturing the order, routing it for approval, allocating inventory, tracking order fulfilment and handling exceptions when something goes wrong.

It is worth clarifying that "order management" covers two distinct contexts:

• Seller-side OMS manages orders that customers place with your organisation. These are the kind of systems used by retailers and distributors to fulfil demand.
• Buyer-side OMS manages orders your organisation places with suppliers. These are the tools that matter most for procurement teams.

Most general guides focus on the seller perspective. For procurement decision-makers, the buyer-side capability is what drives the case for investment.

According to McKinsey, procurement typically accounts for 50 to 80 percent of a company's cost base. Yet many organisations have far greater visibility into spend than into the processes that sit behind it. An OMS helps close that gap by bringing structure, visibility and control to the order management process, improving decision-making across the wider supply chain.

OMS vs. ERP

An ERP (enterprise resource planning) system manages the wider business, including finance, HR, accounting and inventory management.

An order management system (OMS) focuses on the order management process, from order entry through to fulfilment and returns. The two systems are complementary rather than competing.

Some ERP platforms include OMS modules, but they may lack the flexibility needed for complex approval environments, high order volumes or multichannel operations.

In simple terms, an OMS manages the order workflow end to end. An ERP records and reports on the financial outcomes of that workflow.

OMS vs. WMS

The simplest distinction is this: an OMS oversees the full order lifecycle, while a WMS manages the physical fulfilment process inside the warehouse.

A warehouse management system (WMS) manages warehouse operations, including picking, packing, stock location and despatch.

An OMS manages the order before it reaches the warehouse and after it leaves, including routing, approvals, order status tracking and refunds.

Many organisations use both systems together, with data shared between them through integrations or an API.

How an order management system works

Understanding what an OMS does in practice means tracing what happens to an order at each stage and identifying where, without a system in place, things tend to go wrong.

Without an OMS, procurement teams typically rely on a patchwork of spreadsheets, email threads and manual checks. Common problems include stale inventory levels, orders stuck in approval queues, manual routing errors and confusion when returns or delivery disputes need to be resolved. When information is spread across multiple systems, it becomes harder to track orders and maintain a reliable audit trail.

The order management lifecycle

A well-configured OMS moves every purchase through seven key stages of order processing:

1. Order capture (requisition): The buyer raises a purchase request, specifying the item, quantity, supplier and cost centre. The OMS creates a structured record from the outset.
2. Validation and approval: The order is checked against policy: spend thresholds, authorised suppliers, budget availability. Approval is routed automatically to the right person or team.
3. Inventory allocation: Available stock is confirmed and reserved, preventing double-ordering or purchasing items already in stock. This helps maintain accurate inventory levels and supports real-time inventory visibility.
4. Routing to fulfilment: The order is directed to the appropriate fulfilment location or supplier, based on stock levels, delivery zones and service level requirements.
5. Despatch and tracking: The buyer receives tracking information and can monitor order status without chasing the supplier directly.
6. Delivery confirmation: Receipt is logged against the original order, enabling three-way matching with the purchase order and invoice.
7. Returns management: If goods arrive damaged or incorrect, the OMS manages the returns workflow, updating records and initiating credit where applicable. This supports reverse logistics and helps you manage refunds more efficiently.

For procurement managers, the stages that deliver the clearest ROI are order capture, validation and approval and returns management, where manual processes are most likely to create delays and additional work.

Why manual order management breaks down

Visibility remains a challenge for many procurement teams. According to Ardent Partners’ CPO Rising 2025 report, procurement teams do not actively control almost 30 percent of organisational spend. The same report found that fewer than 10 percent of organisations have fully automated spend analysis, while more than a quarter still rely on manual reporting.

Common failure points include:

Approval workflows bypass policy. Email approvals and verbal sign-off make it harder to enforce spend controls and preferred supplier rules.

No single view of open orders. Procurement teams struggle to see what has been ordered, received or is still outstanding, making reconciliation more time-consuming.

Delayed invoice matching. HMRC requires VAT-registered businesses to maintain accurate records of purchase transactions. But when invoices and purchase orders sit in different systems, matching becomes slower and more error-prone. This is the operational gap that AP automation is designed to close.

Order discrepancies take longer to resolve. Missing records make it harder to investigate incorrect deliveries, quantity disputes, and supplier errors, which can ultimately affect customer satisfaction.

These risks become operationally significant for organisations managing more than 75 purchase orders per week or those working with multiple suppliers across different categories.

Key features of an order management system

Not every OMS feature matters equally. The capabilities below have the biggest impact on procurement performance, compliance and efficiency.

Real-time inventory visibility

Real-time inventory visibility means stock counts updated within seconds of any transaction, across all locations and channels. Before raising a purchase order, buyers need to know what is actually available before committing budget to a reorder.

Stale inventory data leads to duplicate orders, unnecessary stockouts and rushed reorders at premium cost. An OMS with real-time inventory data reduces the gap between what the system shows and what is actually available.

Order routing and fulfilment automation

Rather than manually deciding which supplier or warehouse should fulfil an order, an OMS routes orders automatically based on inventory levels, delivery zones and service level commitments. The goal is to get the right product from the right location at the right time to meet customer expectations. Consistent fulfilment creates a more reliable customer experience and reduces disruption for internal teams.

But when that routing is handled poorly, costs start to accumulate. Split deliveries generate additional invoices, inconsistent lead times make planning harder and partial shipments complicate reconciliation.

Approval workflows and purchasing compliance

This is the capability that matters most for procurement decision-makers and the one most often absent from general OMS guides written from a retail or logistics perspective.

A well-configured approval workflow defines who can authorise a purchase, at what spend threshold and how that decision is recorded. The OMS enforces those rules automatically, preventing unauthorised purchases, flagging orders that exceed budget limits and routing high-value orders to the appropriate approver.

Approval workflows also support compliance. An OMS creates an audit trail of purchasing decisions, purchase order records and approval activity that supports VAT reporting, internal governance and external audits. This is a core part of what a well-run procure-to-pay process looks like in practice.

Amazon Business addresses this directly. Buying Policies and Approvals allows procurement managers to configure spend thresholds and authorised supplier lists at the point of purchase, helping enforce policy before an order is placed.

Integration with existing systems

An OMS does not operate in isolation. The three most common integration points for UK procurement teams are:

• ERP systems (SAP, Oracle, Microsoft Dynamics) for financial data, budget checking, forecasting and invoice matching
• Warehouse and logistics systems for delivery tracking and stock confirmation
• E-procurement platforms (Coupa, Jaggaer, SAP Ariba) for catalogue management and Punchout connectivity

Amazon Business Punchout connects a supplier catalogue directly to a procurement system, allowing orders to follow existing approval workflows and purchasing controls.

Organisations subject to UK GDPR should also confirm that any cloud-based OMS provider stores and processes data within the UK or a compliant jurisdiction.

What to look for when evaluating an OMS

Once you understand how an OMS works, the next step is deciding whether a particular system meets your requirements. According to Deloitte's 2025 Chief Procurement Officer Survey, the top areas of next-generation technology adoption are data analytics (88%), invoice and payment processing (78%) and purchasing (75%). Order management is increasingly being evaluated as part of a broader effort to improve visibility, control and efficiency across the procurement process.

Procurement decision-makers evaluate OMS differently from IT or logistics buyers. The priorities are usually approval workflow flexibility, reporting, auditability and integration with existing systems.

Questions to ask before selecting a system

Use these questions in vendor conversations:

1. How configurable are approval workflows? Can spend thresholds and authoriser hierarchies be set by department, cost centre or category and can they be updated without IT involvement?
2. How does the price change as order volumes, supplier numbers and users increase? What factors have the biggest impact on total cost over time?
3. Can the system generate HMRC-compliant purchase order records? What does the audit trail include and for how long is order history retained?
4. Does it support Punchout integration with your existing ERP or procurement solution? Which systems does it connect to natively and what is the implementation timeline?
5. What is the data retention policy for order history? Where is data stored and does it comply with UK GDPR requirements?
6. Can spend reporting be segmented by cost centre or project code? How granular is the reporting and can it be exported for budget reconciliation?
7. What happens when an order falls outside policy? Is it blocked, flagged or escalated and who receives the notification?

Integration and scalability considerations

An OMS is only as useful as its fit within your existing technology stack. Common integration requirements include ERP systems (SAP, Oracle, Microsoft Dynamics), finance systems (Sage, Xero) and procurement systems (Coupa, Jaggaer, SAP Ariba).

Cloud-native OMS solutions generally offer more flexible APIs and faster integration timelines than legacy on-premise systems. If your organisation expects growth in purchasing activity, supplier numbers or approval complexity, scalability is worth evaluating early.

How Amazon Business simplifies order management

Amazon Business delivers buyer-side order management capabilities directly within the purchasing experience, helping procurement teams streamline orders, approvals and reporting without adding another system to their technology stack.

The relevant capabilities map directly to the features covered above:

• Guided Buying enforces approval workflows and authorised supplier lists at the point of purchase — so procurement policy applies automatically, without requiring buyers to check a separate system.
• Spend Insights provides real-time visibility into purchasing activity by category, supplier and cost centre, making budget reconciliation and reporting significantly easier.
• Order tracking gives buyers and procurement managers a single view of order status across all Amazon Business purchases, reducing the need to chase suppliers directly.
• Punchout integration connects Amazon Business to major ERP and procurement platforms, meaning purchases made through Amazon Business are subject to your organisation's existing approval workflows.
• Prime Business members access additional controls and reporting features.

For procurement teams managing multiple suppliers and dealing with approval compliance gaps, these capabilities address the specific pain points that manual processes leave unresolved.

Take control of your organisation's purchasing process

The cost of poor order management is not only operational, it’s also financial. Manual approval gaps, missing audit trails and unauthorised purchases can lead to unnecessary spending, compliance risks and time lost to reconciliation and investigation.

A practical first step costs nothing. Review one area of your order management process and identify where manual intervention is most common. For many procurement teams, approval workflow visibility is a good place to start. If you cannot see which orders are awaiting approval, who needs to act or where bottlenecks occur, there is likely an opportunity to improve efficiency and control.

If your team buys from multiple suppliers and needs better visibility into approvals and spend, explore how Amazon Business supports procurement compliance for UK organisations.

This article was created by professional writers and editors with the assistance of AI-powered tools. AI was used in a supportive capacity only – for example, to aid with translation, content review, and alignment with brand guidelines. All substantive research, editorial decisions, and final approval were performed exclusively by human authors and editors, who retain full editorial responsibility for this publication.

FAQs about order management systems