“…There are mainly two categories demands in the present studies, one is deterministic demand and the other is stochastic demand. Various formations of consumption tendency have been studied, such as constant demand (Padmanabhan & Vrat, 1990;Chung & Lin, 2001;Benkherouf et al, 2003;Chu et al, 2004), level-dependent demand (Giri & Choudhuri, 1998;Chung et al, 2000;Bhattacharya, 2005;Wu et al, 2006), price dependent demand (Wee & Law, 1999;Abad, 1996Abad, , 2001, time dependent demand (Resh et al, 1976;Henery, 1979;Sachan, 1984;Dave, 1989;Teng, 1996;Teng et al, 2002;Skouri & Papachristos, 2002;Panda et al, 2012;Sett et al, 2013;Mishra et al, 2013) and time and price dependent demand (Wee, 1995). Among them, ramp type demand is a special type of time dependent demand.…”