In recent years, remanufacturing has emerged as an important research area. This requires developing methods and models in order to aid companies in systematically evaluating current as well as projected remanufacturing systems. This paper addresses the inventory control problem in a hybrid inventory system with manufacturing and remanufacturing options. In this study, by changing the definition of inventory position of the serviceable stock, we introduce a shift PULL inventory control policy, which is compared with PULL, DUAL, and Separate PULL control policies studied previously in the literature. Besides evaluating the economic consequences with different control policies, we also study system dynamic behaviour such as the bullwhip effect, in order to understand the advantages and disadvantages of different policies. After the experiments, we propose several management guidelines for such a hybrid inventory system. The major findings are: (1) separate PULL and DUAL can be good alternatives when the manufacturing lead time is significantly longer than the remanufacturing lead time; (2) shifted PULL exhibits a good performance when the two lead times differ slightly. Owing to the complexity in solving the optimization problem, a simulation approach is used.

Attention to energy efficiency is recently experiencing substantial growth. To overcome the several barriers currently existing that represent an obstacle to the successful implementation of the wide set of energy efficiency measures available, the cooperation among members of a supply chain offers a huge potential. In supply chains, in addition to the traditional coordination of the operations, the members may also share financial resources or act jointly on the capital market. This study presents a two-stage supply chain model considering the opportunity to invest in new energy efficient technologies which are affected by learning effects: the member of the supply chain with better energy performance and/or better financial conditions may find it more profitable to invest in the development of the energy efficiency of its partner. The objective of the model is to determine the optimal investment for each supply chain member so as to maximize the Net Present Value of the supply chain. The impacts of the proposed joint decision-making are investigated through some numerical analysis and managerial insights are proposed: the joint decision-making process on the financial flows for the energy efficiency investments results are especially advantageous (up to a 20% increase of the supply chain Net Present Value) when members have different access to capital, which could be the result of different economic conditions in companies’ countries, as well as different credit policies or different credit ratings.

In the context of enhanced decision making related to Industry 4.0 and 5.0, this work examines the first step toward the implementation of a Digital Twin (DT) in a discrete manufacturing firm. It will be required that the DT be adequately integrated with the information systems, especially the Manufacturing Execution System (MES), because the virtual counterpart of the DT itself, a Discrete Event Simulator (DES) model, will exploit the MES data for the validation and monitoring. The objective of the DT is to enhance the decision making related to production planning in particular, achieving better on-time delivery to customers. Therefore, the DT intends to depict material flows within the production department to enhance the monitoring and control, facilitating the prompt identification of deviations from the plan and supporting the decision-makers, enabling a more responsive and informed management of delay alerts. The first goal to achieve the DT implementation and integration is to establish a conceptual framework that improves material flow data synchronization. A conceptual integration and implementation framework for the DT will be proposed and discussed, underlying the technical decisions chosen to achieve the functional and integration requirements.