Multi-criteria decision making as a tool for sustainable product development : Benefits and obstacles

For developing sustainable products design engineers need to foresee diverse interrelations between a product's characteristics and its economic, social and environmental impacts. In order to support this complex task a wide range of design methods has been developed. Retrospective analytical methods like Life Cycle Sustainability Assessment (LCSA) require a large amount of information and are thus utilized when important design decisions are already made. Prospective methods are rather generic (e.g. checklists) and too broad to be helpful in concrete design decisions. In this paper, the integration of discrete decision trees with LCSA is proposed for shifting multi-criterial quantitative analysis to earlier development. On the basis of sustainability indicators Pareto-optimal decision-paths for given material- and process alternatives along the product lifecycle can be compared up-front. Resulting benefits and obstacles are illustrated by evaluating value creation options of a bicycle frame

Information Management Platform for the Application of Sustainable Product Development Methods

AbstractA multitude of information is required to address sustainability aspects in product design decisions. However, information required for applying methods in the field of sustainable product development often overlaps. Moreover, specific improvement measures can primarily be identified if method results can be traced back to data origin. This paper presents a concept and implementation of an information platform which is integrated into a PLM system and integrates an ontology based knowledge model and a semantic wiki. The information platform shall avoid double work, improve documentation of information and assist in understanding the data basis of method results. This paper discusses requirements and solution elements and presents findings from applying the methods Lifecycle Design Strategies (LiDS) Wheel and the Product Sustainability Index

Benefits and obstacles of sustainable product development methods : a case study in the field of urban mobility

In the last few years, numerous approaches have been introduced for supporting design engineers in developing more sustainable products. However, so far, these efforts have not led to the establishment of a commonly acknowledged standard methodology for Sustainable Product Development (SPD). This brings into question the relevance of developing new methods and calls for more efforts in testing the available ones. This article provides a reflection about the benefits and obstacles of applying existing SPD approaches to a real product development project. It reports the results of a project aimed at developing a new mobility solution under the constraints of sustainability-related targets. This project has led to the development of a new pedelec concept, focusing on the substitution of small passenger cars with the help of three SPD methods – Design for Sustainability Guidelines, Product Sustainability Index, and Life Cycle Sustainability Assessment. These methods have proved to be generally beneficial, thanks to a combination of qualitative and quantitative perspectives. However, the multitude of criteria offered by the methods put forth difficulties in evaluating which sustainability aspects are relevant and therefore lead to higher effort for information retrieval analysis and decision processes. Furthermore, the methods still lack an integrated perspective on the product, the corresponding services and the overarching system.DFG, 325093850, Open Access Publizieren 2017 - 2018 / Technische Universität Berli

Tracing the Dark Matter Sheet in Phase Space

The primordial velocity dispersion of dark matter is small compared to the velocities attained during structure formation. The initial density distribution is close to uniform and it occupies an initial sheet in phase space that is single valued in velocity space. Because of gravitational forces this three dimensional manifold evolves in phase space without ever tearing, conserving phase-space volume and preserving the connectivity of nearby points. N-body simulations already follow the motion of this sheet in phase space. This fact can be used to extract full fine-grained phase-space-structure information from existing cosmological N-body simulations. Particles are considered as the vertices of an unstructured three dimensional mesh, moving in six dimensional phase-space. On this mesh, mass density and momentum are uniquely defined. We show how to obtain the space density of the fluid, detect caustics, and count the number of streams as well as their individual contributions to any point in configuration-space. We calculate the bulk velocity, local velocity dispersions, and densities from the sheet - all without averaging over control volumes. This gives a wealth of new information about dark matter fluid flow which had previously been thought of as inaccessible to N-body simulations. We outline how this mapping may be used to create new accurate collisionless fluid simulation codes that may be able to overcome the sparse sampling and unphysical two-body effects that plague current N-body techniques.Comment: MNRAS submitted; 17 pages, 19 figures; revised in line with referee's comments, results unchange

Multi-scale initial conditions for cosmological simulations

We discuss a new algorithm to generate multi-scale initial conditions with multiple levels of refinements for cosmological "zoom-in" simulations. The method uses an adaptive convolution of Gaussian white noise with a real space transfer function kernel together with an adaptive multi-grid Poisson solver to generate displacements and velocities following first (1LPT) or second order Lagrangian perturbation theory (2LPT). The new algorithm achieves RMS relative errors of order 10^(-4) for displacements and velocities in the refinement region and thus improves in terms of errors by about two orders of magnitude over previous approaches. In addition, errors are localized at coarse-fine boundaries and do not suffer from Fourier-space induced interference ringing. An optional hybrid multi-grid and Fast Fourier Transform (FFT) based scheme is introduced which has identical Fourier space behaviour as traditional approaches. Using a suite of re-simulations of a galaxy cluster halo our real space based approach is found to reproduce correlation functions, density profiles, key halo properties and subhalo abundances with per cent level accuracy. Finally, we generalize our approach for two-component baryon and dark-matter simulations and demonstrate that the power spectrum evolution is in excellent agreement with linear perturbation theory. For initial baryon density fields, it is suggested to use the local Lagrangian approximation in order to generate a density field for mesh based codes that is consistent with Lagrangian perturbation theory instead of the current practice of using the Eulerian linearly scaled densities.Comment: 22 pages, 24 figures. MNRAS in press. Updated affiliation

Assistenzsystem für die Entwicklung nachhaltiger Produkte

Entscheidungen in der Produktentwicklung definieren die Gestalt und Wirkungsweise eines Produktes und legen damit dessen Lebensweg sowie auftretende Nachhaltigkeitswirkungen fest. IT-basierte Assistenzsysteme bieten das Potenzial, Entwickler bei ihren Entscheidungen zu unterstützen, indem zusätzliche Informationen mit Nachhaltigkeitsbezug für den Entscheidungsträger aufbereitet werden. In dieser Dissertationsarbeit erfolgt daher eine systematische Analyse relevanter Entscheidungssituationen sowie hierfür benötigter Informationen. Kern der vorgeschlagenen Lösung sind modulare „Building-Blocks“, welche es Unternehmen erlauben, selbstständig Assistenzsysteme für die Entwicklung nachhaltiger Produkte aufzubauen. Dieses flexible Konzept ermöglicht eine individuelle Anpassung des Systems an die Charakteristika der Organisation (Prozesse, Methoden, IT-Welt etc.). Um dieses Prinzip zu demonstrieren, werden in der Arbeit drei Umsetzungen eines Assistenzsystems für wesentliche Entscheidungssituationen bei der Entwicklung nachhaltiger Produkte vorgestellt. Diese reichen von übergreifenden Systembetrachtungen über Konzeptentscheidungen auf Produktebene bis hin zur Optimierung einzelner Bauteile

Design Dependencies Visualisation Tool - initial alpha release

Heuristics play a great role in design creativity and learning. There is generally no systematic method designers can be provided with in order to derive optimal design solutions. In other words, it is neither possible to list all solutions to a given problem nor to prove the absolute superiority of a given solution. However, guidance can be provided to designers in the form of heuristics, i.e. set of solutions validated by practice, which have proven to lead towards satisfactory solutions, but which are not guaranteed to be optimal or perfect. Heuristics express a supposed causal relation between two design parameters. For example, in the context of automobile development, “overall weight” has a direct relation with “energy consumption in use.” This tool allows displaying the network built by all causal relations between design parameters. It provides an environment to explore and navigate in this network in order to support creativity in design

Optimiertes Produktdesign: Effizienz über den Lebenszyklus

Im Rahmen des Projektes wurde eine Methode zur prospektiven Integration von Ökobilanz in das Produktdesign entwickelt. Zunächst wird ein Lösungsraum in der Designphase durch Evaluierung gangbarer Konstruktionsvarianten (Material, Geometrie, Fertigungsprozess) aufgespannt und anschließend anhand von Ressourceneffizienzkriterien die erstrebenswerteste Lösung ausgewählt. Auf dieser Basis kann die jeweilige Variante dann auskonstruiert werden. Der hierfür notwendige Prozess ist in den Arbeitsplatz von Entwicklungsingenieuren integriert