Terry Crowley:

 I struggled with how to think about complexity through much of my career, especially during the ten years I spent leading Office development. Modeling complexity impacted how we planned major releases, our technical strategy as we moved to new platforms, how we thought about the impact of new technologies, how we competed with Google Apps, how we thought about open source and throughout “frank and open” discussions with Bill Gates on our long term technical strategy for building the Office applications.
 I want to explore the issues I faced then and how our approach was influenced by how I thought about complexity.
 
 I’m currently rereading Melanie Mitchell’s “Complexity: A Guided Tour” and am heartened that even professional academics who study complexity full time have a hard time defining or measuring it. No breakthroughs here, I’m afraid, but let us try to construct a mental model that we can use to explore the topic.
 
 When we think about enhancing a software system, we can consider the curve that measures aggregate functionality against the aggregate cost required to achieve it. My impression from reading journalists and analysts writing about software is that they believe you have a linear curve that generally looks like this: