A safety critical automotive part was produced without defects, but the foundry wanted to improve its yield. No changes in the casting design or the riser contact areas were allowed. Autonomous optimization in MAGMASOFT® was used to redesign risers on both sides of the castings, as well as the ingate and downsprue. First, the outside risers were given a large design window, allowing them to change their shape, size, distance to the casting and vertical location. Constraints were set to allow for sufficient clearance between the castings and the risers, as well as between neighboring risers. In a second step, the inside risers were optimized, but small changes in the outside risers were allowed to compensate for changes in the melt temperature distribution induced by the geometric changes.