For a new product launch, the warehouse ships PDQ display packs to stores, advisers unpack them for individual-box sales, and online customers order from the same stock for store pickup. If four systems each report stock without a clear owner for reservations, the store can receive orders it cannot fulfill.
Start the architecture discussion with the physical and commercial events: arrival at the store, reservation against an order, handover to the customer and return. For each event, establish who records it and who informs the other systems.
Four systems record different business facts
The following is a starting point for defining responsibilities, not a fixed architecture. Explicitly identify the authoritative source for store inventory and for availability across channels.
| System | Typical responsibility in this scenario | Handoff to verify |
|---|---|---|
| Retail system / store POS | Store receipts, unpacking, checkout, pickup, returns, counts and local stock movements | Which document records each store action and which systems receive it |
| ERP | Product, purchasing and financial records under existing brand rules; receipt of inventory and sales results | Product codes, units, store warehouse definitions and posting cutoffs |
| WMS | Central warehouse locations, picking, packing, dispatch and inspection of warehouse returns | SKU and PDQ quantities shipped, and what the store actually receives |
| OMS | Cross-channel order intake, fulfillment routing and order states; reservation ownership depends on the architecture | Assigned store and responsibility for releasing reservations after cancellation or expiry |
A brand does not have to purchase four independent products. Order routing may sit in a commerce platform, or a shared inventory service may calculate availability. Whatever the arrangement, each order event and inventory change needs an identifiable owner.
When does a dispatched PDQ become sellable store stock?
Suppose one SKU has an agreed conversion of one PDQ pack to twelve individual boxes. WMS picks and dispatches packs. When the retail system receives the dispatch information, it may record goods in transit. Store inventory should be posted under the agreed receiving rules only after staff verify the packaging and quantity actually received.
When the store opens a pack for individual sales, the unopened-pack and individual-unit states must follow that physical action. The same goods must not become simultaneously available in both units.
Agree who maintains product codes and conversion ratios, which event creates the conversion record—warehouse dispatch, store receipt or unpacking—and which unit ERP receives. If the store receives one PDQ fewer than dispatched, preserve the warehouse dispatch quantity, actual store receipt and ERP posting outcome as distinct evidence. Resolve the difference through the receipt or discrepancy document rather than replacing one system's original records with another's closing balance.
Opening-stock migration and unit-model design are separate workstreams. For daily operations, the immediate question is which receiving or unpacking event triggers the store and ERP inventory updates.
Separate order allocation, stock reservation and customer pickup
If OMS routes online orders for limited releases, it should select a fulfillment store using the agreed availability and send the order and reservation result to that store. Staff then verify the goods and prepare the order. The system used at the actual handover records customer pickup and sends the result back to the order owner.
Payment received, goods prepared and customer pickup completed are three different milestones. Recording all of them as “complete” obscures whether the customer has actually received the products.
Cancellation and release need equally explicit ownership. Decide who releases reserved units after a customer cancellation, store rejection or missed pickup deadline, and when they become available again. If both retail software and OMS deduct the same reservation, stock is understated. If each waits for the other, new orders may oversell. Where a separate service calculates availability, document its source systems and the reservation and release events it consumes.
Warehouse-direct orders follow a different path. OMS sends the order to the warehouse, and WMS confirms picking, dispatch and physical return receipt. The store retail system should not treat those goods as a local sale or local available stock. For store pickup, define the feedback connecting local handover confirmation to completion in OMS.
Trace returns and exceptions through the original fulfillment path
For a box returned at a store, staff first verify the original transaction, product condition and refund rules. The store records the return and its local stock movement. If the product must go back to the central warehouse, that warehouse subsequently confirms physical receipt. ERP receives the documents needed to reverse the sale or adjust inventory; OMS updates order or refund states where an online order is involved.
A store return, a warehouse return and a completed monetary refund are distinct events. A single “return successful” state must not increase stock at every location.
Use documents to investigate exceptions. A warehouse dispatch without a store receipt, an OMS cancellation with a reservation still held in store, and a completed pickup with the order still awaiting fulfillment require different corrections. Retain the original order, dispatch and receipt references and the time of each state change. The system responsible for the missing step should repair it and notify the others. Compare inventory balances after correcting the documents.
Resolve five questions before launch
Rather than starting with a long interface field list, use one actual product and one store-pickup order. Ask retail operations, warehousing, order management and finance to answer:
- Who maintains the relationship between the SKU, PDQ pack and individual unit, and which in-flight documents retain the old rule after a change?
- Where are central warehouse stock, goods in transit, unopened store packs and sellable individual units recorded?
- Who selects the pickup store, reserves the goods and releases them after cancellation or expiry?
- Which documents establish warehouse dispatch, actual store receipt, customer pickup and physical return receipt?
- Who retransmits failed messages and verifies posting when interfaces fail, repeat a message or show different balances?
The resulting responsibility table should name the system of record, triggering document, recipient, permitted synchronization delay and exception owner for each operation. Follow the same SKU and order reference end to end. That exposes assumptions such as posting store receipt at dispatch or treating payment as pickup.
Persistent balance differences require a separate investigation starting with the first discrepant document. Repeatedly transmitting balances does not resolve unclear responsibility or a missing event.
Where PEKON fits
The PEKON Smart Retail System covers store checkout, inventory and store operations and can connect with existing ERP, OMS and other systems. In this scenario, it handles receiving, transactions and stock actions performed at the store. Product master ownership, cross-channel availability calculations and warehouse operations still need explicit assignment within the brand's existing architecture.
PEKON's collectible toy retail solution describes PDQ-to-smaller-unit conversion and store sales scenarios. Bring actual SKU packaging relationships, warehouse and store codes, order states and sample interface messages to the project. Establish which requirements are standard functionality, configuration, integration or custom development, and check how the existing ERP, WMS and OMS actually receive and post each result.
A useful system boundary is one that can be traced through the product, location, order and document states. A real product's packaging rules and one pickup order provide a practical starting point for the evaluation.
FAQ
Why does the retail system need inventory records if ERP already has a store balance?
ERP may maintain headquarters accounting and summary balances, while store staff receive, unpack, sell and count the goods. The retail system records those actions and their documents, then updates ERP under agreed rules. Align units, definitions and cutoffs before comparing the balances.
If OMS routes orders, must it reserve store stock?
No. OMS can route orders while the retail system or an inventory service manages reservations and releases. Define one effective reservation for each order and the state changes required after rejection, cancellation or pickup.
Can a store make goods available as soon as WMS confirms dispatch?
The store still needs to verify the goods and quantities actually received. Dispatch, transit and receipt describe different locations and times. Preserve shortages or damage as discrepancies and resolve them before determining availability.
Can a brand support store pickup without a standalone OMS?
It may use capabilities in its existing mini-program, commerce platform and retail system. It must still assign order intake, store selection, stock reservation and release, and the destination for pickup confirmation. These responsibilities remain even without a separate OMS product.