Safeguarding Open ZaakBrug integration software for the VNG


Last month we successfully carried out the first implementation of Open ZaakBrug (OZB) at the municipality of Súdwest-Fryslân. In this blog, Jaco de Groot, CTO of WeAreFrank! Will explain what steps have been taken before this.

The municipalities of Súdwest-Fryslân, Haarlem and Utrecht had to get rid of their old case system last year and have opted for the open-source OpenZaak. As one of the first movers, the municipality of Súdwest-Fryslân ran into a problem: namely that the old Case and Document Services (ZDS) are not supported by default in OpenZaak as a result, the existing integration with the older peripheral systems was lost and a solution had to be found.


To solve this problem, Eduard Witteveen, of the municipality of Súdwest-Fryslân, has set up Open ZaakBrug. Initially built as a Proof of Concept (POC) in python a programming language. Open ZaakBrug takes care of the translation of the old ZDS standard into the new Zaakgericht Werken (ZGW) standard.

The municipality of Súdwest-Fryslân then approached the municipalities of Utrecht and Haarlem to test Open ZaakBrug and the problems it solves. Both municipalities recognized the problem existing ZDS integrations were disappearing and were enthusiastic. After further consultation, it turned out that Python was not the right choice for a joint solution. That is why Open ZaakBrug (OZB) was converted from Python to Java code in 2020



Then came the real challenge for the three municipalities, to find a market party that wanted to provide guarantees on the source code and a party that also wanted to implement OZB. For the municipalities, this was ideally one party, who could do the implementation, solve incidents and make improvements to the Java code. In order to make the OZB software production-worthy and to secure the knowledge, it had to land with a large market party with knowledge of integration. This is how municipalities came to WeAreFrank!, The open-source integration specialist in The Netherlands.

In September 2020, WeAreFrank! was approached by the municipalities of Súdwest-Fryslân with whether we as a market party could provide guarantees on the OZB source code and implement the implementation for them on their landscape.


After the first talks, we as WeAreFrank! said yes to the municipality of Súdwest-Fryslân. After given time to review the Java code, we concluded that the municipalities had built an excellent and stable foundation. The biggest change that WeAreFrank! Made, the software was provided with our own Open-Source Ladybug Test Tool. Ladybug is necessary to be able to view the message traffic and thus be able to quickly resolve errors and incidents. Ladybug also allows automated tests to be added to the CI/CD pipeline so that any changes to Open ZaakBrug will automatically run all available tests. By adding Ladybug to Open ZaakBrug, we dare to give a guarantee on the OZB 1.0 production version.Learn more about ladybug.



Last April was the start-up of OpenZaak for the municipality of Súdwest-Fryslân. Parallel to this, we also put the first OpenZaak Brug into production. The first implementation was for their BurgerZaken peripheral system. Soon we will connect the other ZDS peripheral systems together.Read more on commonground



We are grateful to the municipality of Súdwest-Fryslân for choosing us as their implementation partner for OpenZaak Brug. In addition, we would also like to thank the municipality of Utrecht and municipality of Haarlem for their trust in us, that we can contribute to the source code for OpenZaak Brug. Finally, we would like to thank the VNG for promoting the Open-Source philosophy in The Netherlands. As WeAreFrank! We are very proud that we can help build the technical foundation of The Netherlands! The Open ZaakBrug integration solution is free to use for everyone.

Want to make the switch to OpenZaak and Open ZaakBrug? Please feel free to contact us!