‘Constraint based production planning’, what a heavenly tool that would be. You will no doubt recognise a few comments that I have received from this field, which I would like to therefore share with you. “If this order doesn’t fit, the program has to come up with a solution’, or ‘I want to be able to create several simulations and, ultimately, choose the most appropriate one proposed by the system’. Another one: “if I move this order, what impact will that have on the other orders and will the system move this automatically?’ At the end of the day, these are all great theoretical questions or solutions, but once examined in close detail, the exceptions soon became apparent. Unfortunately there were never just a few, often there were dozens. I then asked who would be maintaining these constraints within the company. And who has the authorisation to deviate from the rules? And do we trust blindly in every proposal put forward by the system? Rather important, isn’t it? This usually resulted in a joint consensus to give the planner tools with which he or she has an overview and can easily make decisions. I don’t believe that tools exist that would replace the intelligence of the planner, do you?