An adapted version of the water wave optimization algorithm for the capacitated vehicle routing problem with time windows with application to a real case using probe data

Customers' habits, as far as shipping requests are concerned, have changed in the last decade, due to the fast spread of e-commerce and business to consumer (B2C) systems, thus generating more and more vehicles on the road, traffic congestion and, consequently, more pollution. Trying to partially solve this problem, the operational research field dedicates part of its research to possible ways to optimize transports in terms of costs, travel times, full loads etc., with the aim of reducing inefficiencies and impacts on profit, planet and people, i.e., the well-known triple bottom line approach to sustainability, also thanks to new technologies able to instantly provide probe data, which can detail information as far as the vehicle behavior. In line with this, an adapted version of the metaheuristic water wave optimization algorithm is here presented and applied to the context of the capacitated vehicle routing problem with time windows. This latter one is a particular case of the vehicle routing problem, whose aim is to define the best route in terms of travel time for visiting a set of customers, given the vehicles capacity and time constraints in which some customers need to be visited. The algorithm is then tested on a real case study of an express courier operating in the South of Italy. A nearest neighbor heuristic is applied, as well, to the same set of data, to test the effectiveness and accuracy of the algorithm. Results show a better performance of the proposed metaheuristic, which could improve the journeys by reducing the travel time by up to 23.64%

Optimization of a perishable inventory system: A simulation study in a Ho.Re.Ca. company

The main goal of this paper is to describe the optimization of the inventory management process in a real context of perishable food products. The study involves one of the largest Italian HO.RE.CA. companies, located in the north of Italy and operating as a provider of the catering, commercial and welfare services. A simulation model was set up with the purpose of adapting three traditional reordering policies (i.e. Re-Order Point, Re-Order Cycle, and (s,S)) to a set of products belonging to company's assortment and evaluating the resulting economic outcomes. To this end, each policy was modelled on Microsoft ExcelTM, so as to compute the total cost of inventory management and determine of the minimum cost strategy. A comparison with the current company's performance and that achievable with the optimized policy is also proposed

Environmental benefits of pet food obtained as a result of the valorisation of meat fraction derived from packaged food waste

The 2030 Agenda of the United Nations includes the objective of setting up sustainable production patterns by pursuing several Sustainable Development Goals. Among them, the “Responsible production and consumption” is a key topic in the food production and is strictly connected with the “Climate action”; the crucial point, however, is how to jointly act on all these aspects and apply them in practice. The waste yearly produced in the food chain represent both an ethical, economic and environmental issue. In particular, as far as the recovery of packaged food waste from retailers is concerned, the valorisation of the wasted meat is an extremely relevant issue. Pet food industries could be interested in valorising this waste fraction to replace meat coming from slaughters in their product recipes. This article evaluates the environmental impact of valorising meat fraction from packaged food waste to produce two different recipes of high quality pet food, called Natura and Pâté. A life cycle assessment of the current scenario (traditional pet food production and landfilling of packaged food waste) and of a new one (pet food production using meat fraction from packaged food waste) is carried out applying the ReCiPe 2016 method of impact assessment. Real data have been taken from retailers and pet food manufacturer. The production of pet food using the meat fraction from packaged food waste generates on average lower environmental impacts if compared to the traditional process, in terms of GWP (-56.40%), water consumption (–22.62%), land use (-87.50%) and fossil resource scarcity (-21.78%). Benefits are interesting even if considering the production of Pâté (-14.66%), for which the traditional production process makes use of some slaughter by-products. The proposed industrial process is demonstrated to be sustainable from an environmental point of view and appears to be in line with Sustainable Development Goals (SDGs) 2, 12 and 13

An Analytic Model for Estimating the Economic and Environmental Impact of Food Cold Supply Chain

Cold chain management has gained increasing interest among practitioners, researchers and academics; similarly, sustainability is also proving to be an increasingly critical topic in all supply chains and in cold chains in particular. In line with this, this study proposes a model to estimate the economic and environmental impacts in a food cold supply chain (FCSC). The model intended to estimate the total cost and CO2 emissions of a company operating in the cold supply chain, was carried out in Microsoft Excel™. Specifically, the model reproduces the main FCSC processes, i.e., Product collection, Backroom storage, Product delivery and Reverse logistics. For each process, we have exposed the implemented equations. Results show that the product delivery process is the most critical in both economic and environmental terms. Conversely, product collection and reverse logistics process contribute to the total cost and emission to a limited extent. The results obtained provide useful guidelines for supply chain managers to undertake operation decisions aimed at decreasing the economic and/or environmental impact of a FCSC

Economic and environmental sustainability dimensions of a fashion supply chain: A quantitative model

Paper aim: The paper presents a model to assess the economic and the environmental sustainability dimensions of a fashion supply chain and tests it on a company. Originality: The gap intended to fill is the lack of models in this context having this purpose, and, in general, the necessity to develop models and metrics allowing to quantitatively assess the economic and environmental dimensions of supply chains. Research method: The fashion supply chain has been divided into five processes. Hence, an analytic model was developed by considering the total costs incurring in each process (economic evaluation), and the annual kilograms of CO2 emitted (environmental perspective). The model was then applied to a case study. Data was obtained from interviews with the management. Main findings: Results show that from the economic perspective supply impacts the most, while from the environmental one the most polluting activity is production. Implications for theory and practice: The model is easy to apply and to understand and allows to identify the activities in the supply chain where the majority of costs/emissions are generated. It is therefore expected to be useful for undertaking operational decisions aimed at decreasing the economic or environmental impact of a fashion supply chain

The milk collection problem with time constraint: An optimization study integrating simulation

Transport management and vehicle routing problems play a strong role on a company's efficiency and competitiveness. In the food sector, the complexity of the problem grows because of strict constraints. This paper addresses the dairy transportation problem and in particular tries to optimize the milk collection process of a real company. A two-step approach has been proposed to test the current system and solve the routing problem. First, starting from the “As is” collection tours, a travel salesman problem has been modelled. Later, the Nearest Neighbor algorithm has been implemented in order to find a global optimal solution. Finally, a stochastic simulation model integrates the solutions of the previous step in order to test the feasibility of the outcomes, primarily in terms of their capability to meet the time constraints of the tours. Results show that the greedy approach allows less vehicles to be involved, with a good potential on annual cost saving. On the other hand, the simulation outcomes highlight a borderline case, which is not always in line with the time constraints of the problem

A model for assessing economic and environmental sustainability dimensions of a fashion supply chain and a case study

Due to the recent attention gained by sustainability issues in the context of supply chains, the aim of this study is to present a model developed under Microsoft Excel™ for the assessment of the economic and environmental dimensions of a fashion supply chain, sector that deserves particular attention being one of the most polluting in the world. The assessment of the economic dimension is made through the evaluation of the total cost incurred in each process of the supply chain, while the environmental aspect is evaluated in terms of the carbon dioxide emissions generated. Specifically, in this paper the modelling of the warehouse function is detailed. To test the effectiveness of the model a case study is carried out on a fashion company based in the North of Italy; the key results are reported in the manuscript, showing where the majority of costs and emissions are generated. Information obtained from this tool can support the company's management in their operational decisions and show where to focus their attention to enhance the economic and environmental sustainability

A storage assignment simulation model for optimizing processes in an e-commerce warehouse of a fashion supply chain

The wide spread of e-commerce and in general B2C systems brought new challenges to supply chains which had to reconsider part of their systems whilst maintaining the same goal: a high level of customer satisfaction. One of the main functions affected by these challenges is the logistics activity, including warehouse management and transports. Indeed, they now have to face higher orders at the same time, to manage picks demand in specified periods, to increase journeys for reaching various customers geographically dispersed. Optimization and synchronization are essential. To this end and according to the steps of the Deming Cycle, this paper presents the case of a warehouse located in northern Italy whose storage activity was firstly simulated and then successfully implemented so as to optimize the picking activity and consequently the subsequent processes of the outbound flow. Improvements were assessed through determined key performance indicators, monitored before and after the implementation of the new strategy

Assessment of the economic and environmental sustainability of a food cold supply chain

Based on environmental and economic factors, reverse logistics (RL) issues have attracted attention among both academia and practitioners. This study investigates the issue of economic and environmental sustainability evaluation in a food cold supply chain (FCSC), which carries out four main different processes, i.e. product collection, backroom storage, products delivery and RL. For the RL process, which is taken as an example, we have detailed the equations implemented in an analytic model to carry out the computation of the economic and environmental sustainability, while for the remaining processes, we present and discuss only the main results obtained. The model was developed under Microsoft Excel™ and is intended to assess the total cost and CO2 emissions of an important company operating as a cold chain logistics service provider. Results of the model show that the highest total cost and environmental impact are due to the product delivery process. Moreover, the results proposed indicate quite clearly the specific activity component where the FCSC managers should intervene to remove or decrease possible inefficiencies and optimize or increase the sustainability of a FCSC

Problemas cuantitativos y comprensión de conceptos

Los docentes de química a nivel universitario usamos «problemas», habitualmente de tipo cuantitativo, para enseñar y para evaluar. En este trabajo ponemos en duda de que lo hagamos en forma eficaz. Se muestra, a partir de pruebas diagnósticas de pares de problemas (uno cuantitativo y otro cualitativo similar), que muchos estudiantes pueden resolver los problemas cuantitativos sin una adecuada comprensión conceptual.Chemistry professors at university level make use of «problems», usually of a quantitative type, to teach and evaluate. In this article we question the fact of whether they do it in an efficient way. From diagnostic test of pairs of problems (a quantitative and a similar qualitative one) it is shown that many students can solve quantitative problems without an appropriate conceptual comprehension