Assessing the sustainability of biomass supply chains for energy exploitation

Biomass use has increased significantly lately, partly due to conventional fuels price increase. This trend is more evident in rural areas with significant local biomass availability. Biomass may be used in various ways to generate heat. In this work, the focus is on comparing two different biomass energy exploitation supply chains that provide heat at a specific number of customers at a specific cost. The first system is pellets production from biomass and distribution of the pellets to the final customers for use in domestic pellet boilers. The second option is centralized energy co-generation, which entails simultaneous electricity and heat generation. In the latter case, heat is distributed to the customers via a district heating network whereas electricity is fed to the electricity grid. The biomass source examined is locally available agricultural residues and the model is applied to a case study region in Greece. The aim of this work is to determine how these two different biomass exploitation options perform in sustainability terms, including the economic, environmental and social dimensions of sustainability. The effect of trying to optimise separately the economic and environmental dimensions of sustainability on the system design is examined, while at the same time taking into account the social dimension. Furthermore, a bi-objective optimisation is employed, to overcome the limitations of the single-objective optimisation. Both the upstream and the downstream supply chains of the pelletizing/CHP units are modelled

The economic and environmental performance of distribution networks: A case study from the petrochemical industry

Designing a company's distribution network is a challenging task that requires the consideration of different aspects. In this respect, especially trade-offs between, for example, operational costs and customer service are the focus of the companies' attention. However, growing concerns of governments and customers about environmental protection have raised awareness towards the environmental impact of operations. Activities associated with the distribution of products, i.e. transportation and warehousing, are not yet subject to strict environmental regulations, but this situation is expected to change soon. Companies must, therefore, start to concentrate not only on economic but also on environmental aspects in the design of their supply chain. Based on a case study from the petrochemical industry, this paper presents a way to combine both, economic as well as environmental criteria, when evaluating (strategic) distribution network design decisions. The results show a trade-off between total (distribution) costs and transport carbon emissions. (author's abstract

The relevance of outsourcing and leagile strategies in performance optimization of an integrated process planning and scheduling

Over the past few years growing global competition has forced the manufacturing industries to upgrade their old production strategies with the modern day approaches. As a result, recent interest has been developed towards finding an appropriate policy that could enable them to compete with others, and facilitate them to emerge as a market winner. Keeping in mind the abovementioned facts, in this paper the authors have proposed an integrated process planning and scheduling model inheriting the salient features of outsourcing, and leagile principles to compete in the existing market scenario. The paper also proposes a model based on leagile principles, where the integrated planning management has been practiced. In the present work a scheduling problem has been considered and overall minimization of makespan has been aimed. The paper shows the relevance of both the strategies in performance enhancement of the industries, in terms of their reduced makespan. The authors have also proposed a new hybrid Enhanced Swift Converging Simulated Annealing (ESCSA) algorithm, to solve the complex real-time scheduling problems. The proposed algorithm inherits the prominent features of the Genetic Algorithm (GA), Simulated Annealing (SA), and the Fuzzy Logic Controller (FLC). The ESCSA algorithm reduces the makespan significantly in less computational time and number of iterations. The efficacy of the proposed algorithm has been shown by comparing the results with GA, SA, Tabu, and hybrid Tabu-SA optimization methods

A Sustainable Supply Chain Model of Relationship Between Wood Supplier and Furniture Industry in Indonesia

Wooden furniture industry is an important industry sector in Indonesia, because many people\u27s welfare relyon this industry sector and the industry has a big social and environmental impacts. Many wooden furnitureindustries in Indonesia, especially in Central Java Province face problems related to the sustainability. The relationbetween wood suppliers and furniture industry is studied in this paper. A sustainable supply chain management (s-SCM) model is proposed as an approach for solutions for the problems. The approach is chosen due to the characteristics of the problems that related to economic, social, and environmental problems. This aim of this paper is to determine how much supply teak wood must be provided by PP to satisfy furniture industry demand, how much production capacity that must be increased and how large forest area that must be planted in order to achieve environmental and social goals without sacrificing economical goals much. Goal programming (GP) is chosen for solving the problems, because the goals are to maximize the total benefit,minimize the total loss and anticipate the conflicts between goals. Numerical trial based on observation in teak wooden furniture industry in Central Java was used to illustrate our findings. Using pareto efficient principle, the model can satisfy all goals that need to be achieved. Numerical results can be used by decision makers in teak wood industry to analyze the trade-off among several set of alternative solutions

Multi Site Coordination using a Multi-Agent System

A new approach of coordination of decisions in a multi site system is proposed. It is based this approach on a multi-agent concept and on the principle of distributed network of enterprises. For this purpose, each enterprise is defined as autonomous and performs simultaneously at the local and global levels. The basic component of our approach is a so-called Virtual Enterprise Node (VEN), where the enterprise network is represented as a set of tiers (like in a product breakdown structure). Within the network, each partner constitutes a VEN, which is in contact with several customers and suppliers. Exchanges between the VENs ensure the autonomy of decision, and guarantiee the consistency of information and material flows. Only two complementary VEN agents are necessary: one for external interactions, the Negotiator Agent (NA) and one for the planning of internal decisions, the Planner Agent (PA). If supply problems occur in the network, two other agents are defined: the Tier Negotiator Agent (TNA) working at the tier level only and the Supply Chain Mediator Agent (SCMA) working at the level of the enterprise network. These two agents are only active when the perturbation occurs. Otherwise, the VENs process the flow of information alone. With this new approach, managing enterprise network becomes much more transparent and looks like managing a simple enterprise in the network. The use of a Multi-Agent System (MAS) allows physical distribution of the decisional system, and procures a heterarchical organization structure with a decentralized control that guaranties the autonomy of each entity and the flexibility of the network