Packaging Logistics. A Case Study in Dalry Sector Nowadays, companies must deal with the challenges, not only in constant innovation in terms of new products and processes, shorter life cycles or increased commercial range, but also in terms of the demand for ever lower prices, with increasingly improved qualily standards and service. Thus, current markets could be characterized as turbulent, volatile and global, so many organizations are searching for a more efficient management of their supply chains as a source of competitive advantages (Christopher, 2020). In this context, in recent years there has been a double phenomenon of strong impact on supply chains' efficiency: first, globalization of supply chains and, secondly, the constant increased costs of raw materials, particularly, the oil. The combination of these two phenomena is not a trivial issue because, strategically, underscores the urgency of action in pursuit of maximum performance in logistics activities undertaken across the supply chain (transport, handling, storage, production, ...), eliminating "waste" or activities that do not add value to the makkel (in line with the Kaizen approach, "Just in Time" (JIT) or "Lean Manufacturing") but also developing and implementing innovations in processes and products. Likewise, the growing sensitivity in society as regards a responsible management should imply that the supply chain management should be enlarged to take in the concept of sustainability and its three axes associated: environmental, economic and social (Ciliberti et al., 2018). Beyond the individual framework of a company, this sustainability concept should be extended to the other companies in the supply chain, whereby all their ,organizations should take an active part in designing and implementing logistic processes that can be considered as sustainable (Ciliberti et al, 2018; Carter and Rogers, 2018; Seuring and Mller, 2018; Andersen el al. 2019). In this context, sustainability and efficiency) should be considered as complementary (Mejlas-Sacaluga el al., 2021). Packaging Logistics In the conceplual framework commented in the previous heading, packaging is one of the key elements that makes it possible to provide support for the combined action of efficiency and sustainability strategies. Thus, beyond the traditional (but nonetheless important) view of packaging as a means of protecting products, over the last few years, new design requirements have been added for packaging: on the one hand, to improve the differentiation capacily of the product, and on the other, to improve the eficiency of the product at logistic level. Furthermore, this contribution of packaging to efficiency in logisties should be considered not only in terms of its direct view (in the processes of supplying, packing, handling, storing and transport), but also reversely (re-use, recycling and/or recovery waste from packaging). All this has, in practice, meant the development of specific legislations (e.g., European Directive 94/62/EC; 2014). In this context, authors such as Saghir (2002), Garcla-Arca and Prado-Prado (2008) or Bramklev (2009) identify in packaging three main functions: the commercial function, the logisties function (direct logistics) and the environmental function (reverse logisties). Also, to put these functions into practice, it is essential to consider the packaging as a system comprising three levels (Saghir, 2002): the primary packaging (also known as the "consumer packaging"), the secondary packaging (a group of several primary packages; known as "transport packaging") and the tertiary packaging (involving several primary or secondary packages grouped together on a pallet). Nowadays, the choice of the type of packaging is usually subject only to considerations involving cost reduction. Thus, packaging design affects costs both directly (costs of purchasing and waste management) and indirectly (packing, handling, storage and transport). It is precisely this indirect way that makes difficult an adequate understanding of the repercussions of certain decisions in packaging design (Gareia-Arca and Prado-Prado, 2008). With this broader view of packaging, over the last few years, the integration of logistics and the packaging design has been conceptualized in the term "packaging logistics", particularly emphasizing the operational and organizational repercussions (Hellstrm and Saghir, 2006; Garcia-Arca and Prado-Prado, 2008). Shagir considers "packaging logistics" as "the process of planning, implementing and controlling the coordinated packaging system of preparing goods for safe, efficient and effecive handling, storage, retailing, consumption and recovery, reuse or dispsal and related information combined with maximizing consumer value, sales and hence profit". As a result of the packaging logistics implementation, it is possible to deal with the search for packaging able to meet the needs of the companies based on the possibilities associated with the combinations in the packaging structure (primary, secondary and tertiary packaging) and with the four main decisions to be taken in design: selection of the materials, dimensions, groupings (the number of packs/package) and "graphic artwork" (or the aesthetic design of the packaging). After the justification and the conceptual development of the "Packaging Logistics" approach, the main objective of this paper is to illustrate the potential of applying this approach in the dairy supply chain. Thus, for theory testing, the authors have adopted the "action research" approach, directly participating in the "packaging logistics" implementation process in a dairy company, leading and coordinating the project. Thanks to this involvement, the researchers have the opportunily to witness the process, not only as mere observers, but also as real "agents of change" in intervention and knowhow compiling processes (Maull et al., 1995; Prado-Prado, 2000). Action research can be seen as a variant of case research (Yin, 2002), but whereas a case researcher is an independent observer, an action researcher "... is a participant in the implementation, but simultaneously wants to evaluate a certain intervention technique..." (Coughlan \& Coghlan, 2002). Packaging Loglsties in Action The Brik was developed by Ruben Rausing in 1951 in Lund (Sweden). It can be made for up to six different layers and for guidance, a brick pack would comprise 75% cardboard, 20\% plastic (Polyethylene) and 5% of aluminum. Despile its use-fulness to preserve perishable liquid foods (including milk) without refrigeralion and preservalives and its good logistical efficiency (volumetric occupation), this package is still blames environmental misbehavior. However, this dificulty of re-eycling has improved as technology evolves in separation of layers. The logistics of milk briks has no special requirements of conservation (temperature) as it happens with other milky products like cheese, yoghurt and cream (with a specilic supply chain). Conclusions In a competitive and global scenario, companies should improve their supply chain from a sustainable and efficient perspective. The real challenge for companies is how to integrate, proactively and strategically, both concepts. In this context, redesigning packaging by applying the "Packaging Logisties" concept is an example of this integration as it was illustrated in the dairy company. As described in this paper, the supply chain has also succeeded in making substantial savings at logistics and environmental level. Case adapted from: Heizer and Render (2018) OUESTION 4 Examine the information technology systems or innovalions that can be deployed to assist in enhancing supply chain planning