I'm sorry, if I may, that 18 months, as far as I could read, was basically “no longer than”. It wasn't a target. It should not take more than 18 months. If my boss came to me and said, “I don't want this to take longer than one week,” I'm going to set a target of three days, so that at day five, at the end of that workweek, he or she definitely has from me what was asked for.
What did you do to respond to said target?