How Aardling advised Portbase to automate Customs logistics using Domain-Driven Design

Case study

  • Domain modelling
Portbase (2)

Aardling guided Portbase in implementing Domain-Driven Design for a centralised, adaptable, and EU-compliant RTO


  • By facilitating data sharing between companies and information exchange with Customs, Portbase contributes to a fast and cost efficient way of working in the Dutch ports.

  • The goal of the RTO project is to reduce overhead created by moving goods into a temporary storage for customs checks and get to a unified RTO administration within the Dutch ports.

  • Aardling modelled the complex rules and processes to support the strategic decision-making process.

  • The model created during the sessions is still applicable, which allows Portbase’s development team to code more efficiently.

About Portbase

Portbase was established by the Port of Rotterdam and the Port of Amsterdam to build world-class digital ports.

Their harbour logistics hub connects companies and authorities to provide efficient data exchange and reduce administration tasks.

As experts on software strategy, modelling, and design, Aardling was brought in to advise Portbase on their new system for Temporary Storage Facilities (RTO).

What is an RTO?

An RTO is a customs approved area in a port, where non-Union goods are placed in storage prior to being placed under a customs entry procedure or re-exported.

Each terminal nowadays maintains their own RTO administration, which causes differences in the way of working and causes lack of transparency for Customs.

Changes in regulation also mean that all terminals must co-evolve their software systems at the same time. Causing a lot of overhead within the community of deep-sea terminals.


Portbase identified the opportunity to create an RTO system for all deep-sea terminals, resulting in unified agreements and way of working between terminals and customs.

This gives future opportunities for paperless transferring of cargo between terminals and a port-wide dashboard for Customs, all bounded in a comprehensive Container Tracking System.

For these type of complex projects Domain-Driven Design has proven its value. Aardling was invited to advise and guide Portbase in using Domain Driven Design to get to a centralised, uniform, adaptable and easier to evolve RTO that will reduce administrative work for its stakeholders and comply with EU legislation.

During the Domain Discovery and Modelling sessions, Aardling consultants and the Portbase staff identified key domain concepts, events, and processes related to RTOs.

They used EventStorming to map out the flow of events, activities, and decisions involved in the RTO process. This allowed them to identify areas of inefficiency, duplication of effort, and potential for errors.

These sessions are crucial to the process to bring forward the complexities of the project and align with stakeholders.

“I was lucky to work with knowledgeable and proactive people. One of the factors that made this a successful project was how quickly they started implementing the ideas from the modelling sessions, giving us a great iterative feedback loop. When things were unclear, the team did the necessary research to get answers within a day.”

Thomas Coopman

Aardling lead consultant for Portbase

It was during this process where the critical workflows were uncovered: dealing with import, export, domestic, transhipments, full and empty containers, setting up documentation for shipments months in advance, and other important scenarios such as moving goods from a damaged container to a new one, or transfers between different facilities. There was a lot the teams needed to agree on and understand.

"In the early sessions with Thomas, we realised that each team was using different terminology with subtle differences in the language. So, for the first few sessions, we spent a lot of time discussing this. To be honest, I found this a little bit frustrating, but I realised how helpful it was since we were able to align and have our terminologies very clear. Everyone was up to speed in the terminologies, and we were to arrive to a flow very easily. This was super important to have.”



Another key breakthrough was finding a different model for each workflow. By mapping out all the flows separately, and analysing them for similarities and differences, the group figured out a set of core flows that allowed them to be extended for different scenarios. The identification of different models for each workflow and the development of core flows will pave the way for a more efficient, adaptable, and collaborative RTO design process.

“Now, when we dive into complex situations, we go back to our model, and it is still very solid. It has proved to be a powerful starting point.”



During the sessions, Thomas was also able to identify several simple core scenarios. This allowed the group to build up to more complex scenarios. By creating variations of the underlying models, the pros and cons of each variation could be evaluated. They modelled how the different workflows interacted. This allowed the team to explore a lot of cases before building the code.

“The sessions allowed for rich discussions that we wouldn’t have the time for otherwise. In them, we were able to identify the problem, explore several different solutions and pick one - which I’m still very happy with even today months after those sessions.”



The solution

As it is often the case, software teams start losing the overview of the core business once complexity starts adding up. But at Portbase, software modelling has become part of their toolkit.

Now, each time a new detail comes up on their RTO project, they go back to the original model created to keep the big-picture overview fresh in their minds.

The identification of core flows also allows for all stakeholders to work from a common framework and easily communicate and share information.

“It was very helpful to have Aardling’s expertise. They were able to provide unique perspectives on real case scenarios combining the business knowledge with the tech solution.”



Through this collaborative effort, Portbase was able to agree on a solution that met the needs of their stakeholders to reduce administrative tasks and improve transparency.

Aardling believes that a successful implementation of this new RTO system will demonstrate the value of collaborative and iterative design processes in complex software design projects.

The RTO system will be launched by the end of the year.

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