“…Besides system dynamics, other simulation methods such as discrete-event simulation, artificial intelligence etc. has been employed to model the dynamical behavior (Alfaro & Sepulveda, 2006;Holmstrom & Hameri, 1999) and possible improvements of SNs (Holweg & Bicheno, 2002). However, most of these studies were still based on the assumption that the SN structure was deterministic and stable.…”