“…'Volume bundling', which refers to the consolidation of demand and (1) increasing the purchase volume for quotation (Karjalainen, 2011;Prince et al, 2013;Schoenherr and Mabert, 2008); 'Price evaluation', which refers to forming price targets and analysing (2) suppliers' bids and cost structures (Ellram, 1996;Newman and Krehbiel, 2007;Romano and Formentini, 2012); 'Extension of supply base', pertaining to increasing the number of (3) sources and bidders per request for quotation to raise bargaining power (Caniëls and Gelderman, 2007;Lonsdale, 2001;McMillan, 1990); 'Product optimisation', referring to modifications to the design, functions (4) and materials of the purchased items (Handfield et al, 1999;Khan et al, 2008;Luo et al, 2011;McGinnis and Vallopra, 1999;Smith, 1999;Wagner, 2012); 'Process optimisation', which refers to efficient and effective processes (5) related to the buyer-seller interfaces (Foster Jr et al, 2011;Labro, 2006;Manrodt and Vitasek, 2004;Quintens et al, 2006a); 'Optimisation of supply relationship', which pertains to establishing and (6) maintaining a long-term, mutually beneficial, privileged relationship between buyer and supplier (Adobor and McMullen, 2014;Blonska et al, 2013;Handfield et al, 2000;Hüttinger et al, 2012;Krause et al, 2007;Nagati and Rebolledo, 2013;Schiele et al, 2012a); and 'Category-spanning optimisation', which relates to balancing trade-offs (7) among multiple sourcing categories (e.g., design changes in a common platform) and adopting mutual approaches, applied by otherwise distinct sourcing teams (D...…”