Selling through a webshop, POS and other channels does not have to create mismatched stock levels. The starting point is one central stock record, clear reservation rules and a known path for every change. Inventory synchronisation then does not merely copy numbers at intervals. It transfers events while controlling delays, errors and exceptions.
A retailer often sees the same item in several places: the ERP, webshop, POS, warehouse or a partner channel. When every channel can change quantity independently, differences appear quickly. A webshop may accept an order for the last unit while a sales associate issues an invoice in a store at the same time. Manual reconciliation then trails behind actual activity.
The most common causes of mismatched stock are not only technical outages. Unclear business rules can also cause the problem:
The question is therefore not only, "How many units do we have?" It is more important to distinguish physical quantity, reserved quantity and quantity available for a new sale.
The first process decision is this: which system maintains the official inventory record? In a controlled model, one system owns the central stock record. This is often the ERP because it can bring together purchasing, warehousing, fulfilment, returns and accounting entries. However, this role should not be assumed. It needs to be explicitly defined for every flow.
The owner of the central stock record should receive or confirm events that change inventory, such as:
The webshop, POS and other sales channels can show availability and submit sales events, but they should not independently create competing versions of the truth. This division of responsibility simplifies investigation. When a discrepancy appears, the team knows where to check the official record and which route the change should have taken.
With Connected operations , it is important to consider sales, warehousing and financial effects as connected processes rather than separate screens. A stock movement without a clear business document is difficult to explain and even harder to correct later.
The term "stock level" often covers several different quantities. For multi-channel sales, it is useful to maintain at least these concepts:
A simple availability model can start with physical quantity less active reservations and blocked goods. The actual formula, however, depends on business rules. Some retailers want to include confirmed incoming goods, while others want to offer only goods that are physically available. Both approaches require clearly labelled statuses and consistent application across ERP, webshop and POS.
The reservation point deserves particular attention. Reserving goods when an order is submitted reduces the risk of overselling, but raises questions about payment, data checks and how long stock is held. Reserving only after payment confirmation reduces the number of blocked items, but increases the chance that another channel sells the same item before confirmation. There is no universal rule. The choice should follow the type of goods, payment method and acceptable operational risk.
Sending a full stock level periodically can be useful as an additional check, but it is not enough on its own for active channels. Sales, cancellations, returns and adjustments can occur between two updates. Inventory synchronisation therefore needs a clear flow of events and responses.
For each event, it is useful to know:
Sequence matters. If a channel processes a sale before an older stock change, displayed availability may be wrong even though both messages arrived technically. The system should therefore identify duplicates, retain the connection to the source event and prevent the same change from being posted more than once when it is resent.
It may not always be possible to eliminate synchronisation delay completely. The aim of the process is not to promise instant transfer in every circumstance. It is to make delay visible and define a procedure for working during an interruption. For example, a channel may temporarily show more conservative availability while the team receives a list of orders awaiting confirmation from the central record.
Assume a central warehouse has five units of an item. Two units are already reserved for confirmed orders. Under the rules, the webshop and POS may offer three units.
If the webshop receives a new order for two units, it should immediately send a reservation request to the owner of the central stock record or apply an agreed allocation mechanism. Once the reservation is confirmed, availability drops to one unit. If the POS attempts to sell two units at the same time, the system should recognise insufficient availability and start a predefined procedure - for example, partial fulfilment, an alternative item, later delivery or manual review.
A weak model only updates the number in channels at set intervals. In that case, both channels can briefly offer three units. A sound model does not assume the conflict will never occur. It defines who confirms the reservation, which event takes precedence and how the decision is recorded.
No integration removes exceptions. The difference is whether they remain hidden in email and spreadsheets or enter a visible work queue. For multi-channel sales, it is useful to define exception categories and responsible roles.
Typical exceptions include:
For each category, define an owner, an internal review time and an allowed correction. It is important to retain an audit trail: the source event, the action taken, the person or system that processed it and the reason for the decision. This record supports operational resolution, stocktakes and analysis of recurring issues.
Connecting ERP, webshop and POS does not begin with a connector. It begins with data and decisions. Before linking channels, review:
The trade-off is often between greater sales availability and lower overselling risk. More aggressive availability can expand the offer, but requires stronger reservation control and a team ready to handle exceptions. A more conservative safety buffer reduces conflicts, but can hide goods that are genuinely available. The right level should reflect item value, sales speed, the ability to provide substitutes and the cost of an error.
A practical next step is not immediately a new integration. It is to trace one item from goods receipt through to return. Record where physical quantity is created, when a reservation is made, which system confirms availability, what is sent to each channel and who handles a failed update.
This map quickly reveals manual handovers, duplicate entries and unclear responsibilities. If you plan to organise multi-channel sales or review an existing flow between ERP, webshop and POS, Talk to the ORKA team about the process rules and points worth clarifying before changing systems.