“…With the complexity of products, the need for simultaneous monitoring of multiple quality characteristics appeared and caused the first economic design of the Hotelling T 2 control charts developed by Montgomery and Klatt (1972). In most of the research works such as Heikes, Montgomery, and Yeung (1974), Yang and Rahim (2006), Chen, Hsieh, and Chang (2007), Seif, Moghadam, Faraz, and Heuchenne (2011), Bahiraee and Raissi (2014), Faraz, Heuchenne, Saniga, and Costa (2014)the economic design of T 2 control chart is presented with single assignable cause Jolayemi and Berrettoni (1989) generalized Duncan (1971) cost model, and produce economic design of T 2 control chart with multiple assignable causes.…”