It's been anniversary time in my personal micro-universe recently. September marks 10 years since we started to use color sticky notes with Peter Coad's analysis technique.

September 1997 Mega-Pattern

The initial domain modeling on Singapore was scheduled for the whole month of September. Peter Coad was leading the effort with a core team of about 6 folks that included Stephen Palmer and me. We rotated others through the sessions every day to give the whole team exposure to the analysis and modeling technique and the domain knowledge. Each day we had different folks from the business analysis team present as subject matter experts. As the days went by we gradually filled up the wall space and the windows with model fragments. The art work was removed from the walls and stored in another room.

Peter had recently (Spring 2007) published the second edition of the "legos" book, Object Models: Strategies, Patterns and Applications. In this book, he presented a recurring pattern in domains using stereotypes. He called these <<role>>, <<moment-interval>>, <<person, place or thing>>, <<description>> this represented an evolution from the earlier first edition of the book from 1995. The mega-pattern as it was being called was also up on the wall as a reminder to us all of the pattern we wanted to achieve with our model fragments.

One morning during the coffee break, Peter and I were left in the room staring at some of the model drawn in yellow sticky notes that had emerged that day and comparing it with other pieces from earlier days. After some minutes of quietly staring with our own thoughts, we looked at each other and almost simultaneously said, "color would help here." I left the room and found Steven Lo, the department admin, and asked him if the sticky notes were available in any other color than yellow? He nodded and disappeared, coming back moments later with a packet containing the now famous 4 pastel colors - yellow, pink, green and blue. I took them to Peter and left them with him. I went off to get coffee and check email.

When the team returned Peter had selected the four colors as displayed above with pink for <<moment-interval>>, green for <<person, place or thing>>, blue for <<description>> and I believe yellow remaining for role. We set about redrawing the models with the colors. It was obvious to us all very quickly how much more information was communicated with the color sticky notes indicating the stereotype of the class.

What we didn't have in September 1997 was the Domain Neutral Component pattern. Nor were we using the term, archetype. Those didn't emerge until Peter was writing the UML in Color book during 1998. Archetype replaced stereotype because Philip Bradley, the team lead on the data tier development, pushed Peter very hard on what he was really trying to communicate with the meta-class indicated by the color of the class. The outcome was that while we might use <<stereotype>> tags, the term stereotype was inadequate. Archetype was a better fit and hence color archetypes were born in December 1998.

The Domain Neutral Component emerged in January 1999 while the UML in Color book was being finished. Peter completely trashed the first chapter of the book and re-wrote overnight. He sent us all a new draft for review and in it was the Domain Neutral Component. I remember that at first we were skeptical. Some of us more than others. I vaguely remember Stephen Palmer taking some months before he bought in to the idea that this one pattern covered everything. Amazingly, 10 years later we all still believe that it does and we haven't managed to improve on it, nor has a 5th archetype emerged.

Domain Neutral Component January 1999

The only modification to the DNC from 1999 that was made was to include the ability for pink <<moment-interval>> classes to have blue <<description>> classes. Peter actually knew he needed this edition but somehow didn't have enough examples prior to sending the book to print. He made the correction very early afterwards and I believe some of the later print run featured the corrected DNC pattern. Technorati tag: Agile, Software+Engineering, David+Anderson, Peter+Coad, Stephen+Palmer, UML, Domain+Modeling, FDD