Los principios básicos de la ordenación territorial del Estado

Along with attempting to implement sustainable operations, due to pressures facing companies, an SC should measure its performance by profits and its impact on the environment and society.

Considerable research effort has been expended on this sustainable SCM issue, which has proven to be a continuingly important research stream. As SC managers need a framework and practical tools to support their decisions, this demonstrates a rich opportunity for researchers to develop formal models for handling various chain activities in sustainable ways.

The relative wealth of literature on quantitative modelling for sustainable SCM indicates the extent to which the models and practical tools have been a focus of sustainable SCM research to date. Finding a trade-off point between sustainability and the economic dimensions based on Pareto optimality has been widely selected as the decision goal (Seuring, 2013). This literature review has illustrated a range of techniques and solution approaches employed within model-based quantitative research. A challenge for researchers is to develop appropriate stochastic modelling approaches to capture a more realistic uncertain decision environment for sustainable SCM (Brandenburg et al., 2014). Through this review, it can be found that extensive research has been done in terms of the environmental dimension of sustainability. It is clear that carbon- efficient SCM is a key area for future research and a means to progress the efforts to reduce global emissions. Considering business practices, operational policies and coordination as the driving sources of emissions is underexplored in the reviewed literature and yet could hold the key to addressing the issues associated with curbing carbon emissions. There has been limited research into how production, inventory, transportation and general SC decisions can be harnessed to achieve environmental sustainability. Significant development in inventory issues is considered lacking (Hassini et al., 2012) and research literature to date has been limited in terms of inventory operations related

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emissions. This oversight may be because the emissions from inventory storage is particularly difficult to measure or less visible than transportation of products (Dekker et al., 2012), or it may not represent a vital source of emissions for firms involving products without deterioration.It is clear from the reviewed literature that energy consumption from SC activities or fixed emissions or environmental impact factor per a choice of unit conforming to the SC activity is considered in quantitative models as the measurement of the SC environmental sustainability (Soysal et al., 2014). Overall, it has to be concluded that studying carbon footprint measurement and integrating this environmental concern with the decision-making should offer interesting insights to better understand, quantify and analyse the impact of carbon emissions across SCs.

As is apparent from the reviewed literature, food industries and sustainability have both relevance and a growing presence within the SCM field. While several sustainability measures relevant to food SCs are considered in the reviewed literature, there are few practical measures commonly used in the research such as those related to consumption and product quality categories in the performance measurement framework explicitly owing to the perishable nature of food products. While the small body of sustainable SCM literature recognises the relevance of the waste problem to a perishable food SC, only selected studies take a more explicit approach towards modelling food waste across the SC. Properly modelling the changes in food properties, such as quality degradation or a decrease in lifetime throughout the network, would be of significant benefit. Related to this is an effort to reduce energy consumption in the temperature control process as well as associated carbon emissions along the chain, which would allow for better environmental efficiency. This is an area that deserves further, informed research.

Among the available literature, one approach (Bozorgi et al., 2014) explicitly mentions environmental sustainability in an inventory model of cold chain items. However, Bozorgi’s approach towards environmental sustainability is related to emissions during transportation and warehousing, and not on perishability. Some recent approaches look at temperature and its influence on quality degradation of perishable food in relation to sustainable SCs (van der Vorst et al., 2009, Rong et al., 2011, Zanoni and Zavanella, 2012, Yu and Nagurney,

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2013). Rong et al. (2011) and Yu and Nagurney (2013) take the food waste problem into account by considering the waste disposal cost. However, including the amount of food wasted along the SC in the modelling approach can be useful as waste also means resource consumption and could be used to evaluate the impact of decisions on the nature and timing of operations and delivery.

The inclusion of environmental impacts produced by operational activities in a multi-objective approach was seen in some recent work (You et al., 2012, Govindan et al., 2014, Soysal et al., 2014), but still seems to be in its infancy. Govindan et al. (2014) proposed a hybrid metaheuristic algorithm with the use of Pareto front as an archieve. In an alternative approach, You et al. (2012) and Soysal et al. (2014) used an ε-constraint method and the Pareto frontiers to observe trade-off relationships between cost and emissions objectives. Regarding the trade-offs in a multi-objective model, Bouchery et al. (2012) approached the inventory problem by using an interactive procedure that accounted for decision makers’ preferences for non-perishable products.

In sum, there are still significant opportunities for researchers to identify efficient ways to improve sustainability measures, to address the issues associated with curbing carbon emissions, to reduce the impacts of food waste problems and to develop models that would improve the possibility for a practical approach to sustainability through decision-making in a stochastic environment to minimise the environmental impact of SC operations, which are currently lacking.

3.4 Summary

The interactions among profit, planet and people bring about SC decisions towards less resource consumption, less waste disposal and lower generation of greenhouse gases. The management of a sustainable SC requires practical and solid tools such as an appropriate framework and model that can help SC managers to address the multitude of decisions, to set priorities, to make decisions that are both financially and sustainably sound and to demonstrate their environmental and ethical behaviour.

Different categories of models and tools capable of reflecting key real-world dimensions and holding moderate solving difficulties are employed by literature

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in dealing with the SCM sustainability problem in accordance with the sustainability aspects considered, the goal relations set by the management, the purpose of the model environment studied, the type of the problem situation analysed, the technique used for problem formulation and the solution approach applied to obtain an answer to the problem.

Following the regulation imposed on carbon emissions, the interactions of firms can be modelled under different schemes of carbon tax, agreed carbon target or emissions trading. In an SC, the processes involved in different phases of decisions, i.e. strategic, tactical, and operational decisions, do consume energy and emit carbon and other wastages. The amount of carbon emissions depends on the performance of various product and process drivers of the SC whilst having production operations and transportation as the two major sources. Approaches employed in literature to measure carbon emissions from production and inventory operations and transportation activities, as well as emissions in SCs involving chain partners, have been described and discussed. Under an assumption that emissions are measurable and quantifiable, firms are documenting the carbon footprint of their activities with a variety of support. When measuring the environmental impacts generated within a food SC, a performance measurement framework comprised of five categories, namely consumption, flexibility, responsiveness, product quality and total SC can be used. Literature considering environmental sustainability in food sector including review papers and quantitative models developed has been investigated.

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Chapter 4 Managing Inventory System with