“…(Thiel & Hein, 2002b) (Moon, Chae, & Yeom, 2006) (Mikyeong, Heung Seok, Taewoo, & Keunhyuk, 2007) (Dobrica & Niemelä, 2008) (López, Casallas, & Hoek, 2009) (Helleboogh et al, 2009 Other (CVL, LISA etc.) 20 33% (Thiel & Hein, 2002a) (Savolainen, Oliver, Mannion, & Hailang, 2005) (Ortiz, Pastor, Alonso, Losilla, & de Jódar, 2005) (Eklund, Askerdal, Granholm, Alminger, & Axelsson, 2005) (Andersson & Bosch, 2005) (Sinnema, Ven, & Deelstra, 2006) (Satyananda, Danhyung, & Sungwon, 2007) (Dhungana, Neumayer, Grünbacher, & Rabiser, 2008) (Kakarontzas, Stamelos, & Katsaros, 2008) (López et al, 2009) (Mann & Rock, 2009) (Brito et al, 2009 23% (14 papers) of the selected primary studies described how to represent variability using an ADL, with a number of different ADLs adopted. The ADLs used for addressing variability were:…”