“…The NDEA approach, however, provides that the modeling (note 1) is adapted to the specific system. NDEA applications are relatively recent but growing [for example (Chodakowska & Nazarko, 2017), (Kao & Hwang, 2008), (Kawaguchi, Tone, & Tsutsui, 2014), (Pinto, 2016), (Prieto & Zofio, 2007), (Sexton & Lewis, 2003), (Wanke & Barros, 2014), (Wanke, Maredza, & Gupta, 2017), ( (Despotis, Koronakos, & Sotiros, 2015), (Chilingerian & Sherman, 2004), (Cook, Hababou, & Tuenter, 2010)]. In this paper we develop a relational multiplicative type NDEA model assuming constant returns to scale for the entire process and for its parts and with four interconnected subsystems.…”