Sigurd Skogestad. Near-optimal operation by self-optimizing control: From process control to marathon running and business systems Published in Comp.Chem.Engng. (2004) Extended version of paper presented at: 8th International Symposium on Process Systems Engineering (PSE'2003), 03-05 Jan. 2004 (original date was 22-27 June 2003), Kunming, China.