Mark Wallace shares a retrospective look at practical applications of constraint programming (CP), starting from the 1990s, when CP gained the most commercial significance. “Constraint Programming has undoubtedly been successful. It has become a standard tool for tackling complex government and industrial applications. Constraints have made a variety of applications, from scheduling to sustainability, more accessible and thereby allowed more applications to be tackled and solved. In practice, CP is typically used as a component of larger systems, and even CP models may be mapped down to hybrid algorithms including MIP, SAT and heuristic methods.

The current obsession with LLMs has taken the focus away from formal modelling and algorithmic problem solving. However, amongst the computer-literate it is recognised that LLMs provide a user interface, but the underlying techniques of modelling and solving, using CP and other technologies, are essential to their practical benefit. In short CP will continue to be a key problem solving tool for years to come!” Link