1,721,026 research outputs found
Inventory Management in Supply Chains: A Reinforcement Learning Approach
No full textA major issue in supply chain inventory management is the coordination of inventory policies adopted by different supply chain actors, such as suppliers, manufacturers, distributors, so as to smooth material flow and minimize costs while responsively meeting customer demand. This paper presents an approach to manage inventory decisions at all stages of the supply chain in an integrated manner. It allows an inventory order policy to be determined, which is aimed at optimizing the performance of the whole supply chain. The approach consists of three techniques: (i) Markov decision processes (MDP) and (ii) an artificial intelligent algorithm to solve MDPs, which is based on (iii) simulation modeling. In particular, the inventory problem is modeled as an MDP and a reinforcement learning (RL) algorithm is used to determine a near optimal inventory policy under an average reward criterion. RL is a simulation-based stochastic technique that proves very efficient particularly when the MDP size is large
Simulating the network structures in the Circular Economy and their impact on resilience
No full textToday need for replacing linear-oriented production systems with circular-oriented ones is urgent. Circular Economy production networks promote the continuous reuse of resources and products, recapturing value from by-products and end-of-life resources, and minimising resource leakage out of the systems. However, the design and management of CE production networks, although representing an important issue worldwide, has been scarcely investigated so far. In this study, we argue that CE networks should be resilient to better face with frequent and unpredictable disruptions and that structural characteristics may influence it. Through a simulation model, we investigate how the node degree connectivity, by affecting the formation of local and global loop structures, influences the network resilience to different types of disrupting events. Results of simulation suggest that in absence of disruptions, a random -like network is characterized by the highest number of long and short cycles. Instead, in presence of disruptions, our results suggest that short cycles are more robust when node degree connectivity is uniformly distributed as occurring in random and small-world -like structures. On the contrary, long cycles result more robust when node degree connectivity is power-law shaped as occurring on scale-free -like structures. Theoretical and managerial implications are discussed
The implications of joint adoption of revenue sharing and advance booking discount programs
No full textConsider a supply chain that consists of a supplier and a retailer, who sells a single product to the customers over a short selling season. In this paper, we present a model in which the supply chain partners participate in two different programs: (1) the supplier and the retailer enter a revenue sharing (RS) contract and (2) the retailer offers an advance booking discount (ABD) program to the customers. Under the RS scheme, the retailer shares a portion of the selling price to the supplier in return for a lower wholesale price. The ABD program is intended to use price discount to entice customers to pre-commit their orders. Besides demand increases, the ABD program allows the retailer to use the pre-committed orders to develop more accurate forecasts. By examining our model, we determine the optimal decisions associated with these two programs including the optimal price discount, optimal order quantity. We analyse the optimal expected channel profit associated with the four possible scenarios wherein each program is offered or not. We also provide a detailed numerical example to illustrate the conditions under which the benefit of the joint adoption of RS and ABD programs is higher than the sum of the benefits associated with separate adoptions of these two program
Making Geographical Clusters more successful: Complexity-based policies
No full textIn recent years there is increasing evidence of the adaptive failure of geographic clusters (GCs) ranging across the US, UK, and other parts of Europe. To explain success and failure in GCs, complexity science is used. It holds that successful GC evolution happens only if they behave as effective complex adaptive systems (CASs). A review of complexity science is offered and suggests seven essential properties of CASs, four from the European and American Schools, and three drawn from the Econophysics School. Furthermore, we suggest that when GCs lose one or more CAS properties they tend to fail. Finally, we suggest policy guidelines, aimed at fostering the GC success. They are based on the seven properties of CASs and are addressed to guarantee that GCs keep all these properties
Ecosystem indicators for measuring industrial symbiosis
Full text linkIndustrial symbiosis (IS) is a collaborative approach among firms involving physical exchanges of materials, energy, and wastes, which creates economic advantages for firms and environmental benefits for the society. In this paper, we adopt an ecosystem approach to conceptualize the network of firms involved in IS relationships (ISN), in terms of organisms (firms), functions (waste exchange), and services (environmental benefits), and provide new insight on how to assess and compute IS performance indicators. In particular, we designed five classes of indicators aimed at assessing 1) the impact of services provided by ISNs on the environment, 2) the performance of the ISN services, 3) how the single functions contribute to ISN services, 4) the performance of the ISN functions, and 5) how the single firms contribute to ISN functions. A numerical example is also discussed showing how to compute them and the information they provide. The proposed indicators are useful to develop proper strategies to increase the efficiency of the system in exploiting the IS synergies, to improve the symbiotic exchanges carried out in ISNs, and to identify firms contributing most to IS benefits. Hence, they may assist managers of ISNs and policymakers in decision-making aspects, an urgent need of the literature
Operations planning and flexibility in a supply chain
No full textIn dynamic competitive markets, the flexibility of manufacturing system networks such as supply chains (SCs) is particularly interesting. The SC flexibility considered in this paper takes into account two main aspects: the process flexibility of each SC firm and the logistics flexibility concerning the possible connections between suppliers, assemblers and markets. Different configurations of an SC are proposed, in correspondence to different degrees of the process and logistics flexibility. The effects of SC flexibility are then investigated on the operations planning performance of an SC Subject to production capacity uncertainty and coping with demand volume and mix variability. In particular, an optimization model is defined to analyse the SC performance in every SC configuration. Managerial guidelines, supporting the management of selecting the appropriate degrees of flexibility and the corresponding SC configuration to be adopted, are finally obtained
Features of the Higher Education for the Circular Economy: The Case of Italy
Full text linkThe higher education system plays a critical role in supporting the transition towards a circular economy (CE). It helps create business leaders and policymakers having appropriate skills, competences, and consciousness referring to the CE challenges. Nevertheless, few studies have specifically investigated how the higher education system is addressing the CE, how the current academic offering is integrating the CE principles, and which skills and competences are currently provided. This paper overcomes these limitations by investigating the current offering of the higher education for the CE in Italy. We analyze the academic programs, courses, and modules at different levels of 49 Italian universities and, by means of a detailed classification of the learning outcomes, provide a clear picture of the knowledge, skills, and competences offered by the CE education. We finally discuss implications of our findings concerning the development of CE education and CE jobs
A fuzzy echelon approach for inventory management in supply chains
No full textThis paper presents a methodology to define a supply chain (SC) inventory management policy, which is based on the concept of echelon stock and fuzzy set theory. In particular, the echelon stock concept is adopted to manage the SC inventory in an integrated manner, whereas fuzzy set theory is used to properly model the uncertainty associated with both market demand and inventory costs (e.g. holding and backorder costs). The methodology is applied on a three stage SC so as to show the ease of implementation. Finally, by adopting simulation, the performance of the three stage SC is assessed and shown to be superior to that, which the adoption of a local inventory management policy would guarantee
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