Decision
Does an OMS replace an ERP, or sit alongside it?
It sits alongside it. An ERP is the system of record for the business — finance, procurement, the books. An OMS operates commerce: orders, inventory, fulfillment and shipments across sales channels. The question comes up so often because both touch inventory, and inventory is where the two look like they overlap.
Different questions
An ERP answers
- What did the business earn and spend?
- What do we owe, and what are we owed?
- What is the financial state of record?
- What did we buy, from whom, at what cost?
An OMS answers
- Where is this order, right now?
- What can we promise on each channel?
- Which warehouse should fulfill this, and what if that fails?
- Why did this ship late, and what did it cost us?
Why inventory causes the confusion
Both systems have a number called inventory, and the numbers are not the same number. The ERP holds a financial and procurement view — what was bought, what is owned, what it cost. Operations needs a commitment view: what can be promised on which channel, accounting for what is reserved, in transit or already sold elsewhere.
Trying to serve the second from the first is where multi-channel operations usually start hurting. It is not that the ERP is wrong; it is answering a different question correctly.
How they connect
Through one connection layer, so neither system has to know how the other is built. mPorts is designed to run alongside the systems a business already has, connecting to them rather than requiring them to be replaced.
Questions buyers ask
- Can we just use our ERP’s order module?
- Sometimes, and it is worth trying before buying anything. It tends to stop scaling when channel count rises, because per-channel commitment rules and fulfillment recovery are not what an ERP order module is shaped for.
- Which one is the source of truth for inventory?
- They are the source of truth for different inventory questions. Deciding explicitly which system owns which question is most of the work in getting the two to coexist.