Rule-based models make IT systems more flexible

Søren Debois develops mathematical models enabling IT systems to be prepared for the constantly changing processes of businesses today.

ResearchComputer Science DepartmentSøren Deboissoftware

What is your current research about?

To put a single headline on it, my research is on flexible working processes. An example we all know is that calling the local government or tax authority and ask them to do something. Sooner or later, the person on the other end will say "I really want to help, but the computer will not let me do it." This indicates that the IT system is not sufficiently flexible - it doesn’t help employees do their jobs.

My field is about better supporting the workflows of a business. When a contractor sets out to develop a large-scale IT system, the consultant typically writes down what the company does, and then develops something that supports this. But it's hard to describe exactly what a company does, you will always forget to take all exceptions into account. I think the solution is to define the rules you work under rather than writing down all processes. This makes getting a model that covers all possible workflows feasible.

What have you discovered so far?

In collaboration with a company called Exformatics, we have investigated how a company actually used an IT system to process applications. I tried to measure how many ways in which they could solve their tasks. My computer gave up after 22 million variants. Presumably, the number was astronomical. This may seem silly, because employees only used about 150 of them. But knowing which 150 variants you actually need is the challenging part of creating IT systems. If we had talked to the employees, we never have come up with exactly these variants. By defining the rules instead – thereby preserving the many possibilities - we ensure that workers have the variants they actually need.

Rule-based models also make systems far more flexible. If you want to change the procedures, you usually have to call a developer who charges a high price to code something and deliver the product a year later. With a rule-based system, it’s super easy to add new ways of doing things.

What do you find most exciting about your field?

Covering the entire span from very theoretical considerations on calculating things in an abstract sense to actual use by a municipal worker. Bringing research with a theoretical dimension into the real world is an art.

Further information

Søren Debois, Associate Professor, phone 7218 5187, email

Vibeke Arildsen, Press Officer, phone 2555 0447, email