What Sets an OMS Apart from Other Business Systems?

When evaluating software for your e-commerce operations, you’ll encounter overlapping terminology: ERP, WMS, IMS, OMS. Here’s what each actually does and when you need which.

The Alphabet Soup

ERP (Enterprise Resource Planning) — Broad platforms that handle accounting, HR, inventory, manufacturing, and orders. SAP, Oracle NetSuite, Microsoft Dynamics. Powerful but complex, often requiring 6-12 months of implementation and $50k+ in consulting. Overkill for most mid-market e-commerce.

WMS (Warehouse Management System) — Focuses on physical warehouse operations: receiving, put-away, picking paths, packing stations, shipping. Manhattan, Blue Yonder, Körber. Great for optimizing warehouse floor efficiency but doesn’t handle order routing or channel integration.

IMS (Inventory Management System) — Tracks what you have and where. Answers “How many blue widgets in stock?” but doesn’t route orders or manage fulfillment workflow. Often a module within other systems.

OMS (Order Management System) — Sits between your sales channels and your warehouse. Takes orders from multiple sources, decides how to fulfill them, tracks the lifecycle, syncs status back. The orchestration layer.

What an OMS Actually Does

Channel aggregation — Pull orders from multiple sales channels into one view (Shopify and WooCommerce today, more coming soon)
Routing logic — Decide which warehouse fulfills each order based on inventory, location, shipping speed, or custom rules
Split shipments — Automatically handle orders that need items from multiple warehouses
Inventory reservation — Reserve stock when orders come in, release on cancellation
Status tracking — 17-state order lifecycle from pending to delivered
Channel sync — Push tracking numbers and status updates back to your stores

OMS vs. WMS: The Confusion

People often conflate OMS and WMS. Here’s the distinction:

OMS decides WHAT to fulfill and WHERE. It routes order #12345 to your Phoenix warehouse because that’s where the inventory is and it’s closest to the customer.

WMS decides HOW to fulfill. It generates the pick path, assigns the picker, tracks the packing station, and prints the label.

You can have an OMS without a WMS (use spreadsheets or simple pick lists). You can have a WMS without an OMS (manually assign orders to warehouses). Most operations need both, or an OMS with “WMS-lite” capabilities built in.

When Do You Need an OMS?

You probably don’t need one if:

Single warehouse, single channel
Under 100 orders/day
Shopify admin handles everything fine

You probably need one if:

Multiple warehouses or 3PL partners
Multiple sales channels (Shopify + WooCommerce, with more channels coming)
500+ orders/day
Spending more time managing orders than fulfilling them
Customer service can’t answer “where’s my order?” without checking 3 systems

The Build vs. Buy Question

Some teams try to build order management in spreadsheets or custom code. This works until:

You add a second warehouse
You add another sales channel
You need to handle split shipments
You need real-time inventory across channels
Someone quits and takes the spreadsheet knowledge with them

At that point, the cost of a proper OMS is less than the cost of the chaos.

Vectis is an OMS built for mid-market e-commerce. Multi-warehouse routing, channel aggregation, package-first fulfillment. See how it works.