I think for those programming complex systems in business and industry, the biggest problem remains how to represent concepts in code. Even the simplest proble

I think for those programming complex systems in business and industry, the biggest problem remains how to represent concepts in code. Even the simplest problem, like a Purchaser placing a Purchase Order for a Product from a Supplier can't be easily modeled and programmed by the majority of software developers - with any sort of predictability based on prior art or their own experience. At best, we approach a problem with a combination of modular procedural code (modularity via subroutines)(from the 1950's) and structured programming with functional decomposition (from the 1960's). There is no shortage of technical prowess, but a warehouse system is not based on design patterns, libraries, frameworks, or technologies. Instead, it is based on people, places, things and transactions interacting together to solve a problem. How to represent real-world concepts and systems (real or abstract) into code, remains the challenge it always has been. We just don't seem to learn any lessons from the past.