Bee Charging Solutions: Billing & Invoicing Solution

Bee Charging, Sweden's leading public Charge Point Operator, were switching their billing solution from one ERP system to another. Other drastic changes were also planned in their IT landscape and they tasked Metergram to help with both crafting the new architecture, implementing a new billing engine in their CSMS, and finally integrating it with the new ERP system.

Challenge

There were two main challenges in this project. Firstly, the new billing engine needed to account for ever growing business requirements. Charging sessions were created not only within the client’s own ecosystem but also via partner networks using both proprietary API integrations, as well as peer-to-peer and hub roaming scenarios. The business logic involving calculation and rating of the session costs was complex, handling numerous tariff and subscription types, coupled with customer categories ranging from end consumers to fleet companies and revenue sharing site owners and partners.

The second challenge was the actual integration with the ERP system that monthly would process payments via both card processing and traditional invoices via mail. Synchronization and accuracy was of the utmost importance, made complicated due to large volumes of data, and sessions coming in from the network with a lag due to e.g. offline chargers or troubled roaming connections.

Solution

To address the first challenge, we created a new billing service that lived separately from the current monolith, yet within the same CSMS ecosystem. In a combination of real-time processing and monthly scheduled tasks, it consolidated the different invoicing strategies, separating CDRs from the different eMSP actors, fleet customers, and revenue sharing partners. This was a complex task from both technical and business perspective and much effort was put on embedding with the client’s financial and accounting team to fully understand and draft the new requirements.

As part of the second challenge, it was determined that a single source of truth was crucial so the solution was designed with this in mind. An immutable universal record format (based on JSON) and storage was defined. This data was then transferred to the ERP system for billing and payment processing first via a separate service, serving as a “preview” interface to the finance and accounting department. Using this service they could define exclusion rules for accounts and customers, and make manual accounting adjustments where needed.

Needles to say, an extremely thorough testing and roll-out plan was put into place. Using different environments, dry-runs and other QA approaches, the end-to-end flow was secured and validated every step of the way.

Outcome

Metergram’s engagement in the new billing and payment project was successfully completed within time, scope and budget and soon in production. A new streamlined business process was put in place supported by the team.

The design approach of having a consolidated, immutable single source of truth at the origin, containing detailed and marked up CDRs enabled the client to theoretically track every single kWh spent in its entire network, attributing it to an account or cost center in the ERP system. This gave the finance and controller function in the company a holistic view, with a whole new level of traceability. As a result, operations could be streamlined and revenue optimized. As an added benefit, Metergram later was engaged to build out a new flow for automatic reimbursement to partners, based on the success of this project and its architecture, creating even further efficiencies in the operations.