Order Management System (OMS) Requirements Checklist for Multi-Channel Retailers

Once you sell on your own site, two marketplaces, and a few physical stores, spreadsheets and plugin-level order handling stop scaling. This checklist is for ecommerce businesses, operations heads, and product owners who are writing requirements for a new order management system, whether they plan to buy one, build one, or extend what they have.

Use it to agree internally on what "must have" means before you speak to a single vendor.

1. Before you start: baseline your operation

• [ ] List every sales channel (own storefront, each marketplace, social commerce, B2B portal, POS, call centre)
• [ ] Record current average and peak daily order volume, and your 24-month growth projection
• [ ] List every stock location: own warehouses, 3PLs, dark stores, retail stores, marketplace-fulfilled stock
• [ ] Map your fulfilment models in use today and planned (ship-from-warehouse, ship-from-store, BOPIS, curbside, drop-ship, split shipments)
• [ ] Identify the system of record for products, prices, customers, and inventory (usually ERP or PIM, not the OMS)
• [ ] Document the top five order problems your team fixes manually every week

2. Order capture and orchestration

• [ ] Ingests orders from all channels into one normalised order model, with the source channel preserved
• [ ] Handles channel-specific rules: cancellation windows, dispatch SLAs, packing slip formats, and return windows differ by marketplace
• [ ] Supports order edits after placement (address change, item swap, cancellation of one line) with an audit trail
• [ ] Holds orders for fraud review, payment verification, or COD confirmation before release
• [ ] Supports pre-orders, backorders, bundles/kits, and gift orders
• [ ] Captures payment at the right point (authorise on order, capture on ship) for each payment method

3. Inventory visibility

• [ ] Calculates available-to-promise (ATP) across all locations in near real time
• [ ] Supports safety stock and channel-level allocation (e.g., reserve 10% for your own site)
• [ ] Pushes inventory updates to every channel automatically, with a defined maximum lag you can measure
• [ ] Reserves stock at order placement and releases it on cancellation or timeout
• [ ] Shows in-transit and inbound stock separately from sellable stock

4. Routing and fulfilment rules

• [ ] Rules-based routing by distance, stock level, cost to ship, location capacity, and delivery promise
• [ ] Automatic order splitting when a single location cannot fulfil, with a limit on the number of splits
• [ ] Store fulfilment workflows (pick, pack, handover) that work on a tablet or phone
• [ ] Carrier selection and label generation, or a clean handoff to your shipping software
• [ ] Rules are editable by operations staff without a developer release

5. Returns and exceptions

• [ ] Customer-initiated returns with reason codes, per-channel return windows, and eligibility rules
• [ ] Buy-online-return-in-store (BORIS) if you have stores
• [ ] Refund, exchange, and store-credit flows linked back to the original payment
• [ ] Restock vs. write-off decision captured at inspection, updating inventory correctly
• [ ] Exception queues for stuck orders (payment failed, no stock, carrier rejected) with alerts

6. Integrations

• [ ] Every integration uses documented APIs or webhooks, not screen scraping or manual CSV drops
• [ ] Failed syncs retry automatically and surface in a dashboard
• [ ] Tax and invoicing meet local rules (for Indian sellers: GST invoicing and e-invoicing thresholds)

7. Non-functional requirements

• [ ] Proven throughput at 3–5x your current peak (ask for load-test evidence, not a brochure number)
• [ ] Role-based access for warehouse, store, support, and finance users
• [ ] Complete audit log of every status change and who made it
• [ ] Data export in bulk, so you are never locked in
• [ ] Clear uptime SLA and support hours that match your trading hours

Red flags to watch for

• Inventory sync described as "every few hours"
• Routing rules that need vendor professional services for every change
• Marketplace connectors maintained by a third party with no SLA
• No sandbox environment for testing integrations
• Pricing that scales per order in a way that punishes your peak season

How to use this checklist

Tick the items that apply, then mark each as must-have, should-have, or nice-to-have. Share the list with operations, finance, and customer support before finalising it, because each team will add requirements the others miss. Turn the must-haves into scripted demo scenarios and ask every vendor to run the same scenarios live.

How Syslabs helps

Syslabs works with retailers on the unglamorous part of order management: API integration between storefronts, marketplaces, WMS, and ERP, along with procurement and inventory automation that keeps stock numbers honest across channels. If you are planning a custom ERP integration or an OMS rollout, we can help turn this checklist into a scoped requirements document.