If I'm not mistaken, closing up the approach actually means joining the two points on the STAR that are not closed (ie. certain STARs end at the downwind Termination waypoint and require vectors to the final approach course fix. By closing the approach, the controller is essentially allowing the aircraft to fly the STAR and upon arriving at the DTW, to fly direct the FACF and then fly the approach (and therefore no longer requiring vectors). This can be done when traffic allows it, but the STAR is built with a DTW so that if there is a lot of traffic, you can essentially extend the downwind with vectors and vector the aircraft to final in its appropriate sequence... any canadian terminal controllers on here want to back me up? (or correct me as the case may be?)