Material Flow Networks as a Means of Optimizing Production Systems

SummaryThis article is the first of a two‐part series that describes and compares the essential features of nine existing “physical economy” approaches for quantifying the material demands of the human economy upon the natural environment. A range of material flow analysis (MFA) and related techniques is assessed and compared in terms of several major dimensions. These include the system boundary identification for material flow sources, extents, and the key socioinstitutional entities containing relevant driving forces, as well as the nature and detailing of system components and flow interconnections, and the comprehensiveness and types of flows and materials covered.Shared conceptual themes of a new wave of physical economy approaches are described with a brief overview of the potential applications of this broad family of methodologies. The evolving and somewhat controversial nature of the characteristics and role that define MFA is examined. This review suggests the need to specify whether MFA is a general metabolic flow measurement procedure that can be applied from micro to macrolevels of economic activity, or a more specific methodology aimed primarily at economy‐wide analyses that “map” the material relations between society and nature. Some alternative options for classifying MFA are introduced for discussion before a more detailed comparative summary of the key methodological features of each approach in the second part of this two‐part article.The review is presented (1) as a reference and resource for the increasing number of policy makers and practitioners involved in industrial ecology and the evaluation of the material basis of economies and the formulation of eco‐efficiency strategies, and (2) to provoke discussion and ongoing dialogue to clarify the many existing areas of discordance in environmental accounting related to material flows, and help consolidate the methodological basis and application of MFA.

The design of production and logistic systems is a process of managing both technical and organisational variants in order to identify the best solution for a given system. This paper discusses design issues of production systems that are applied to an internal logistic system in the automotive industry. As far as the production systems design (PSD) is concerned, three basic classes of software tools usually pertain: computer-aided design (CAD), process simulation, and information systems. However, these software tools have been used with low levels of integration. Vik et al. (2010b, 2010c) proposed integrating these software resources in production systems and developed an advanced tool called integrated design of systems (IDS). The proposed IDS tool involves a wide set of functions for the most common tasks of PSD, from conceptualisation to implementation, including systems analysis (P-Q, cluster, and material flow analysis), automatic generation of simulation models, generation of alternatives for the layout of facilities and factories, material flows display, transportation system design, and iterative buffer size specification. The IDS approach takes advantage of simulation, CAD systems, and their integration. This paper will demonstrate the concept and functionalities of the proposed tool in a real industrial case study.

Data reconciliation consists in modifying noisy or unreliable data in order to make them consistent with a mathematical model (herein a material flow network). The conventional approach relies on least-squares minimization. Here, we use a fuzzy set-based approach, replacing Gaussian likelihood functions by fuzzy intervals, and a leximin criterion. We show that the setting of fuzzy sets provides a generalized approach to the choice of estimated values, that is more flexible and less dependent on oftentimes debatable probabilistic justifications. It potentially encompasses interval-based formulations and the least squares method, by choosing appropriate membership functions and aggregation operations. This paper also lays bare the fact that data reconciliation under the fuzzy set approach is viewed as an information fusion problem, as opposed to the statistical tradition which solves an estimation problem.

Using Material Flow Analysis for Sustainable Materials Management

A review of a series of effective methods in urban metabolism: Material flow, ecological network and factor analysis

Based on the combination of the U.S. economic input-output table and the stocks and flows framework for characterizing anthropogenic metal cycles, this study presents a methodology for building material flow networks of bulk metals in the U.S. economy and applies it to aluminum. The results, which we term the Input-Output Material Flow Networks (IO-MFNs), achieve a complete picture of aluminum flow in the entire U.S. economy and for any chosen industrial sector (illustrated for the Automobile Manufacturing sector). The results are compared with information from our former study on U.S. aluminum stocks and flows to demonstrate the robustness and value of this new methodology. We find that the IO-MFN approach has the following advantages: (1) it helps to uncover the network of material flows in the manufacturing stage in the life cycle of metals; (2) it provides a method that may be less time-consuming but more complete and accurate in estimating new scrap generation, process loss, domestic final demand, and trade of final products of metals, than existing material flow analysis approaches; and, most importantly, (3) it enables the analysis of the material flows of metals in the U.S. economy from a network perspective, rather than merely that of a life cycle chain.

Eco-balance is the basis for the assessing production impact on the environment. Eco-balancing is divided into four phases: goal and scope definition, inventory analysis, impact assessment, interpretation. However, during the creation and evaluation of material flow networks some defects appear which inhibit or make it more difficult to establish realistic statements towards the environmental impact. In order to make a reliable statement about the environmental impact with the help of eco-balance it is necessary to consider all material and energy flows. This chapter gives an overview of the classification of defects in material flow networks. After the classification of data defects the causes of these defects are discussed. In order to resolve the causes of defects some solutions will be presented using the advantages of Petri nets and the application of Fuzzy sets and Rough sets to the Petri nets.

Machine Learning Methods for Prediction of Changes in Material Flow Networks

Coupling Bayesian-Monte Carlo simulations with substance flow analysis for efficient pollutant management: A case study of phosphorus flows in China

This article is a review of advances in sustainability metric (SM), focusing on life cycle assessment (LCA) and material flow analysis (MFA), the most commonly used among all SMs. The presentations at the past 10 Society and Materials (SAM) conferences were used as a database. LCA, the most popular of these methodologies, is thriving among academics, practitioners and clients. Standardized initially by United Nations Environment Program (UNEP) and the European Commission, it passed from the Global North to the Global South and branched into Environmental Product Declarations (EPDs) that provide LCA‐formatted information, initially to the construction sector. Some important issues have progressed but are not completely resolved yet: multifunctional products or processes, circulatory practices, dynamic LCA, regionalization, monetarization, human and eco‐toxicity, biodiversity loss or resource availability, and they need more development work. Although LCA focuses on a microscale vision of the economy, MFA, being macroscale, emphasizes strategic and policy issues, thanks to its dynamic version. MFAs are now available for at least one third of the substances in the periodic table and for countless materials, from metals, to composites and construction aggregates for civil engineering. MFA has shed light on many strategic issues, such as (1) the fate of end‐of‐life goods and of the materials of which they are made, which constitute the so‐called urban mine, (2) the role of stocks in driving material demand and long‐term evolution of production (the so‐called Intensity‐of‐Stock model), (3) the connections with economic and social models that extend the scope and ambition of MFA, and (4) material flow accounting (MFAc), particularly Total Material Requirement (TMR). These two SMs are entirely devoted to objectifying the connection between human activities and the environment, mostly, based on quantitative indicators originating from Sciences, Technology, Engineering and Mathematics (STEM). However, LCA and MFA have left aside the full depth of society’s dynamics, as described by Social Sciences and Humanities (SSH) disciplines. Contributions from SSH disciplines do not match the indicator‐based approach: they explored the concepts of social value of materials and social acceptance, used non‐engineering metaphors to report on hard‐science issues, called on Humanities, from History to Literary Criticism, on Science and Technology Studies (STS), on Design studies, on Ethics or Gender issues to shed light on sustainability issues. How the divide between SSH and SMs can be bridged is not yet fully clear. However, attempts were made to develop approaches that would mimic SMs: Social Cycle of Materials (SCM) mixes Design philosophy with STS, and ANT‐reliant LCA , which posits that materials have agency, takes on board Actor Network Theory (ANT) , a sociological model of society as a whole, to report on objects described by LCA. In between STEM and SSH approaches, lie approaches based on thermodynamics, which claim that physics can tackle social and economic dimensions: thermoeconomics is one of them.

This study describes the preparation of an eco‐balance to document the materials and energy which are part of the beer production process of the Hasseröder Brewery Ltd. A general introduction to eco‐balances and material flow networks is followed by the description of the concrete case study. The modelling of material flows and the derivation of eco‐balances is illustrated with the help of a selected process from beer production. Finally, the possibilities and limitations of the balance evaluation is discussed with the aid of performance measurement systems. The article closes with a preview of future studies.

Materials flow analysis (MFA) is internationally recognized as a key tool to assess the biophysical metabolism of societies and to provide aggregated indicators for environmental pressures of human activities. Economy‐wide MFAs have been compiled for a number of Organisation for Economic Cooperation and Development (OECD) countries, but so far very few studies exist for countries in the South. In this article, the first materials‐flow‐based indicators for Chile are presented. The article analyzes the restructuring of the Chilean economy toward an active integration in the world markets from the perspective of natural resource use in a time series from 1973 to 2000. Special emphasis is placed on the assessment of materials flows related to Chile's international trade relations. Results show that material inputs to the Chilean economy increased by a factor of 6, mainly as a result of the promotion of resource‐intensive exports from the mining, fruit growing, forestry, and fishery sectors. At more than 40 tons, Chile's resource use per capita at present is one of the highest in the world. The article addresses the main shortcomings of the MFA approach, such as weightbased aggregation and the missing links between environmental pressures and impacts, and gives suggestions for methodological improvements and possible extensions of the MFA framework, with the intent of developing MFA into a more powerful tool for policy use.

Brominated flame retardants (BFRs) are synthetic additives mainly used in electrical and electronic appliances and in construction materials. The properties of some BFRs are typical for persistent organic pollutants, and certain BFRs, in particular some polybrominated diphenyl ether (PBDE) congeners and hexabromocyclododecane (HBCD), are suspected to cause adverse health effects. Global consumption of the most demanded BFRs, i.e., penta-, octa-, and decaBDE, tetrabromobisphenol A (TBBPA), and HBCD, has doubled in the 1990s. Only limited and rather uncertain data are available regarding the occurrence of BFRs in consumer goods and waste fractions as well as regarding emissions during use and disposal. The knowledge of anthropogenic substance flows and stocks is essential for early recognition of environmental impacts and effective chemicals management. In this paper, actual levels of penta-, octa-, and decaBDE, TBBPA, and HBCD in waste electrical and electronic equipment (WEEE) as a major carrier of BFRs are presented. These BFRs have been determined in products of a modern Swiss recycling plant applying gas chromatography/electron capture detection and gas chromatography/mass spectrometry analysis. A substance flow analysis (SFA) technique has been used to characterize the flows of target substances in the recycling process from the bulk WEEE input into the output products. Average concentrations in small size WEEE, representing the relevant electric and electronic appliances in WEEE, sampled in 2003 amounted to 34 mg/kg for pentaBDE, 530 mg/kg for octaBDE, 510 mg/kg for decaBDE, 1420 mg/kg for TBBPA (as an additive), 17 mg/kg for HBCD, 5500 mg/kg for bromine, and 1700 mg/kg for antimony. In comparison to data that have been calculated by SFA for Switzerland from literature for the 1990s, these measured concentrations in small size WEEE were 7 times higher for pentaBDE, unexpectedly about 50% lower for decaBDE, and agreed fairly well for TBBPA (as an additive) and octaBDE. Roughly 60% of the total bromine input determined by SFA based on X-ray fluorescence analysis of the output materials of the recycling plant cannot be assigned to the selected BFRs. This is an indication for the presence of other brominated substances as substitutes for PBDEs in electrical and electronic equipment. The presence of BFRs, in particular PBDEs in the low grams per kilogram concentration range, in the fine dust fraction recovered in the off-gas purification system of the recycling plant reveals a high potential for BFR emissions from WEEE management and point out the importance for environmentally sound recycling and disposal technologies for BFR-containing residues.

Purpose: The purpose of this paper is to analyze material flow from the perspective of a logistics operator operating in a distribution network at Material Decoupling Point (MDP). This analysis will focus on classifying the flowing products into the appropriate groups in terms of their sales characteristics, release volume and the value of the coefficient of variation. This analysis will also involve product classification in terms of forecast accuracy. Design/methodology/approach: Main method used for the research focuses on analyzing one of distribution network. Analyze considered examination of material flow and tests of forecast tool to improve operational issues. Findings: Logistics operator is able to forecasting demand of products in distribution network. It is interesting area of research developing in the future. Originality/value Forecasting is considered here as a kind of development perspective for the operator who currently does not make forecasts. Forecasting implementation could be in these case.

Interpretation of material flow analysis results and a case study on cleaner production for wastewater source reduction in a zinc electrolysis cellhouse