From manual government processes to automated B2B and B2G e-invoices: How Westfalen AG meets international requirements with GOpus and ecosio and paves the way to S/4HANA
About Westfalen AG
The Westfalen AG Headquartered in Münster, Westfalen is an internationally active energy and industrial gas company with several business units. Its portfolio includes industrial gases, energy supply, its own network of filling stations in the mobility sector, and medical solutions for respiratory home therapy, such as medical oxygen. In addition to the German market, Westfalen operates various subsidiaries in Austria, Switzerland, Belgium, and the Netherlands. The company focuses on modern, efficient processes and is driving, among other things, the digital transformation of its SAP system landscape.
Project scope
- Implementation of a reliable, scalable and future-proof solution to meet national and international e-invoicing obligations.
- Implementation and integration of e-invoicing processes within SAP by GOpus
- Provision of a secure, validated and legally compliant Peppol connection by ecosio, including validation and transmission
- Building a central, automated end-to-end process directly within the SAP system
Key project results at a glance
- Fully automated sending of structured e-invoices in multiple countries
- Central control and monitoring of all e-invoicing processes within the SAP system of Westfalen AG
- Greater transparency through integrated monitoring and traceable status feedback.
- A future-proof, scalable solution that easily supports additional countries and requirements.
Why Westphalia chose GOpus and how the partnership is structured
Westfalen was looking for a solution for its internal SAP system to implement efficient, legally compliant, and internationally scalable e-invoice processing. The goal was to centrally manage both incoming and outgoing e-invoices and reliably meet the growing regulatory requirements in multiple countries. Westfalen chose GOpus® einvoice because the solution combines deep SAP integration with high process reliability, minimal integration effort, and a ready-made template, while also providing the foundation for international expansion. The implementation was carried out in close collaboration between Westfalen and GOpus and was designed from the outset for long-term stability and future-proofing.
Key reasons for choosing GOpus:
- Seamless integration of GOpus® einvoice into the existing invoicing processes of the SAP system landscape for end-to-end automation of e-invoicing processes with minimal training effort.
- Legally compliant processing of e-invoices and compliance requirements according to national and international regulations in cooperation with ecosio
- Central control/monitoring and transparency across all organizations and broadcast media.
- High flexibility and scalability for future country requirements and process adjustments
- Close, collaborative partnership during implementation and rollout, with clear points of contact and short communication channels.
Initial situation
Westfalen AG previously sent invoices via various channels such as mail, email, PDF, and EDI. This heterogeneous system landscape resulted in high manual effort, limited transparency, and an increased risk of errors – especially in an international context. With the introduction of mandatory B2G e-invoicing in Germany and increasing regulatory requirements in Austria, Belgium, and the Netherlands, the pressure on the internal SAP team to harmonize processes and future-proof them increased.
The most challenging aspect was:
- Operations were running on SAP ECC while preparations were simultaneously underway for the transition to S/4HANA.
- Different legal requirements in Germany, Austria, Belgium and the Netherlands
- Lack of end-to-end transparency regarding shipping status and errors
- High manual effort, e.g., due to the previously necessary uploading of e-invoices to national government portals.
- Different transmission channels and formats that were difficult to scale without central control.
- The need to map different invoice types and processes via customer-specific SAP extensions.
Project launch, conducted entirely remotely
First productive redirect via ecosio
Go-live for Germany and the Netherlands
Connecting Austria — Implementation in only about one week
Then: Extension to Belgium
Summary & Customer Highlights
The successful implementation of the e-invoicing solution at Westfalen AG is based on a clear division of tasks and close collaboration between Westfalen, GOpus, and ecosio. This enabled the rapid establishment of a stable, high-performance, and internationally scalable solution that integrates seamlessly into the existing SAP landscape. Markus Liesche, IT Process Manager for SAP Sales and Logistics at Westfalen AG, particularly emphasizes the solution's high degree of practical applicability.
The structured creation and automated sending of e-invoices are done directly from SAP. The solution is flexibly designed and can be adapted to company-specific processes without creating additional complexity in the specialist departments.
„"I work very intensively with the solution and it is very user-friendly. The tool is flexible and can be adapted to our customer-specific processes."“
For secure and compliant transmission, ecosio handles the validation, routing, and transmission of country-specific formats such as UBL or XRechnung via the Peppol network. This ensures high data quality and significantly reduces the number of rejected invoices.
„"The solution is very transparent and only in very few cases is an invoice rejected."“
Another key benefit is the e-invoice monitor in SAP. All status information – from successful delivery to validation errors – is centrally available there. This enables a quick overview and efficient error analysis directly within the system.
„"For me, this is a clear efficiency advantage. I can see the delivery status of my e-invoices at a glance and am immediately alerted in case of an error.". With the E-Invoice Monitor, I can quickly get an overview, filter, jump to specific sections, and troubleshoot directly.“
Furthermore, manual effort has been significantly reduced. Previous country-specific processes, such as uploading invoices to government portals, are completely eliminated, which considerably relieves the burden on operational teams.
„"The fact that we no longer have to upload anything manually means an enormous time saving."“
The solution's strength is also evident in its international scalability. Thanks to clear structures and well-established collaboration, new countries can be integrated in a very short time.
„"E-invoicing for Austria was implemented in just about one week."he implemented. This is a clear example of the speed at which more countries can be connected.”
Looking to the future, the architecture is already geared towards the planned migration to SAP S/4HANA. Westfalen has therefore decided to continue using the solution long-term.
„"We will continue to use the solution under S/4HANA as well.". The decision has already been made.“
Overall, the partnership between GOpus and ecosio creates a solid foundation for Westphalia to implement future regulatory requirements and international standards efficiently, securely and in a scalable manner.
Interested in learning more about GOpus eInvoice? Sign up now for a free live demo!
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