“…This phenomenon is called the learning effect and research on its presence in manufacturing systems and on advantages following from that fact are being continuously carried out from 1936 (e.g. Argote, 1996;Jackson, 1998;Keachie & Fontana, 1966;Nadler & Smith, 1963;Yelle, 1979;Young, 1991), when this phenomenon was discovered in aircraft industry by Wright (1936). Nevertheless, the learning effect has attracted particular attention in scheduling just only during the last decade as it became clear that scheduling problems with the learning effect allow to describe many settings that occur inter alia in manufacturing, management, businesses and services sectors (for a survey see Biskup, 2008;Janiak & Rudek, 2009).…”