One of the fun things going on over at the Decision Management Community is a series of challenges based on various real or real-ish problems. For each the site encourages folks to develop and submit a decision model to show how the problem described could be solved. This month there was one on Port Clearance Rules
We are looking for a decision model capable to decide if a ship can enter a Dutch port on a certain date. The rules for this challenge are inspired by the international Ship and Port Facility Security Code. They were originally developed for The Game Of Rules, a publication of the Business Rules Platform Netherlands. The authors: Silvie Spreeuwenberg, LibRT; Charlotte Bouvy, Oelan; Martijn Zoet, Zuyd University of Applied Sciences.
For fun I worked this up in DecisionsFirst Modeler (with a little help from Jan Purchase, my co-author on Available now! Real-World Decision Modeling with DMN). I deliberately did not develop the decision tables for this as I wanted to show the power of a decision requirements model. Looking at the model, and asking only the questions that are immediately apparent as you develop the model, was revealing and to me showed the value of a decision model:
- It’s clear what the structure of the problem is
- It’s clear what’s missing
- It’s much easier to see the whole problem than it is to get the gist from a list of rules
I have done this kind of exercise many times – building an initial model from a set of rules or documents – and it never fails to be useful.