Quantitative approaches for the integrated management of agri-food supply chains

Abstract

In recent years, the development of global markets and higher expectations from end customers have forced the supply chain players to better coordinate and integrate their plans, in order to maintain high levels of performance and be competitive on the market. Today, in fact, companies compete not only on product price or quality, but also on the reliability and timeliness of deliveries. Managing a supply chain in an integrated and coordinated manner is even more complicated and challenging, with reference to the agri-food context, where the constraints about quality and safety of goods, that are usually perishable, are much more stringent than in other sectors. By coordinating the various activities, it is possible to make supply chains more efficient and sustainable, as products can be made and distributed in the right quantity, at the right time and to the right customer. In support of integrated planning, new technologies are recently spreading, with the aim of making the sharing of data and information between the various actors safe and efficient. In this regard, the blockchain is among those technologies, whose interest has grown the most in recent months, both from the academic and business world. The present dissertation mainly aims to develop, test and validate novel quantitative approaches for the integrated management of agri-food chains. • In Chapter 2, a review of the main scientific works published in the last 15 years is proposed, referring to the integration of production, storage and distribution activities, via optimization strategies, within perishable supply chains. In this context, in order to identify effectively the different research gaps and to suggest possible future challenges, a five-dimension classification framework is proposed. This review is the starting point for the following 3 chapters, which address as many case studies. • In Chapter 3, an optimization model is designed for the simultaneous management of the storage and distribution of agricultural products. It is used to maximize the profits of a real company, which deals with the planting, growing, harvesting, storage and distribution of cauliflowers to a main customer and to spot customers. A hybrid fresh-/old-first inventory management policy is modeled to balance the quality of the delivered product and limit the amount wasted. The model improves the current practices of the firm and supports effectively the day-to-day decisionmaking regarding the quantities of product, for each age, to be stored and distributed to each customer. • In Chapter 4, a model is instead developed and tested to integrate the activities of production (i.e., harvesting), storage, distribution and routing of perishable agri-products. The case study refers to two companies, located in Southern Italy. At the tactical level, the proposed model determines the optimal value of two important operating parameters: the frequency of the harvesting activities and the service level to be guaranteed to customers. At the operational level, instead, the model is a valid tool to suggest to the company, day-to-day, the optimal quantities to harvest, store, distribute, and the routes to travel to reach customers, in order to maximize profits and contain waste. In this context, considering that the companies of the case study share some customers and are not in competition, as they are heterogeneous in terms of marketed products, the possibility of horizontal collaboration is also explored. The collaboration, as intended in this Chapter, implies that one of the two actors makes its own fleet of vehicles available, in exchange for a fee. In this context, a heuristic framework is proposed and validated. It suggests collaborating day by day, only if collaboration is economically convenient for both the companies. Computational tests, carried out on randomly generated instances, reveal that the collaboration can guarantee significant savings in terms of CO2 emissions and therefore make the supply chain more sustainable. • Chapter 5 deals with the integration of the production, storage and distribution activities of a company in the vegetable sector. In the production field, a scheduling problem is solved, which takes into account the set-up times of the production line, the hourly fluctuations in the energy price and the perishable nature of raw materials. In the distribution field, instead, it is necessary to schedule deliveries in terms of quantity of shipped products and days. The proposed model allows to schedule both production and distribution in an integrated way. Two rescheduling strategies are tested, to adequately react to customer demand, which occurs on a weekly basis. The first reproduces the current behavior of the company, while the second allows to improve current practices and jointly minimize the costs of energy, storage and distribution. • In Chapter 6, considering the recent proliferation of scientific works on the theoretical or practical use of blockchain technology in the agri-food sector, a literature review on this topic is proposed. This tool, since it allows the real-time sharing of information between the various players in the supply chain in a safe and efficient way, can facilitate the coordination of production and distribution plans, which is the main subject of the previous chapters of this thesis work. The aim is to identify current research trends and inform the reader about the degree