In an imperfect world, competition authorities cannot get every case right. Often, the benefit of hindsight allows for an ex-post assessment of antitrust decisions yielding valuable insights. Therefore, a systematic integration of expost analyses may form an important part of due process in the sense of a systematic “controlling” of competition policy (improving future antitrust policy). Competition authorities have a responsibility towards society and companies to reduce error costs in the course of time. Such a “controlling” refers to reviewing past decisions in order to look forward and making better future decisions – in contrast to look backwards and revise past decisions.