SAP OMSA (5) – Functionalities beyond sourcing

André Dotzler

Henning Sanders


In our previous article, we discussed the core feature of OMSA: sourcing. Now, we’ll explore other key functionalities of OMSA that can be accessed via API.

In principle, all information exchange must be initiated by external systems, as SAP OMSA cannot autonomously push information. SAP is working on this feature, which is expected in future releases.


Besides sourcing, a crucial function of OMSA is providing availability information to other systems, such as displaying stock levels in a web shop.

SAP offers the following APIs for this purpose:

  • Availability calculation: Determine how many items are available for a specific strategy using the Strategy ID.
  • Available to sell: Shows how many items are generally available for sale.
  • Available to sell by site: Retrieves availability information for specific locations (e.g., stores or distribution centres) using Site IDs. This feature is particularly useful for displaying store-specific availability.


OMSA not only displays current stock levels but also provides information on expected stock from incoming orders. This data can be communicated to customers using the ATP snapshots from the S/4HANA backend, allowing messages like “Product X available in 3 days.”


Reservations are initially triggered by a sourcing request but may need to be updated based on certain settings. There are three statuses:

  • Temporary: Usually assigned when a user adds a product to their cart; this reservation can expire.
  • Pending: Typically assigned once the checkout process is complete.
  • Confirmed: Assigned when the reservation is successfully created in S/4HANA.


Using an API, the status of a reservation ID can be adjusted at various points. Therefore, the above statuses are just recommendations.

Note: If you use SAP’s Order Management Foundation (OMF), it sends a “Reservation Confirmed” message when an order is created in S/4HANA, eliminating the need for custom development.

Availability Block

To temporarily remove stock from availability, it’s recommended to use an Availability Block. This prevents certain stock from being shown as available or sourced in OMSA without resorting to complex backend adjustments. The Availability Block API requires you specify how long the stock will be marked as unavailable.

Summary and looking ahead

Through its diverse APIs, SAP offers state-of-the-art processes for both inventory calculation and display. Looking to the future, OMSA is expected to be able to push inventory updates, reducing the need for web shops to conduct individual product availability inquiries. SAP is exploring the idea of implementing a Rough Stock Indicator (RSI), similar to the existing model used within the OAA environment.


Interested in learning more about SAP OMSA? Get in touch with us to find out more.

SAP OMSA (4) – Sourcing request

In response to the sourcing request, the SAP OMSA system decides which sites the products should be sourced from. In this article, we look at which information and parameters can be included in the sourcing request.

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SAP OMSA (3) – Sourcing strategy

In the SAP OMSA system, sourcing strategies significantly determine the outcome of a sourcing request. In this article, we take a closer look at sourcing strategy settings and shed light on how they can be used and adapted.

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