Karl G. Mueller

A framework for structured data retrieval in LCA using feature technology

Obtaining the life cycle inventories (LCI) required for life cycle assessment (LCA) is often too expensive to be of use, as data is difficult to obtain and the amount of data is high. Integrating LCA into the design process can only be achieved by automating the extraction of LCI-relevant product data. Product models, that are used in product design, contain information relevant to the LCI and enabling structured access to that data reduces the amount of work for the LCA analyst by avoiding repeated determination and input of LCI data (data redundancy). This paper introduces a framework for a structured data retrieval in an LCA context through the use of feature technology. In a product model that includes a feature model, information on design features (e.g. geometry, dimensions) and manufacturing properties (e.g. material used, machining process applied) are included. Structured and efficient access to the LCI relevant data can be realized by a dedicated application program interface (API) bridging the gap between an LCA program and the product model. The characteristics and basic functionality of the API are described and the advantages of using an API are discussed. The basic idea of the framework is illustrated with a designed part.

Efficient Information Visualization in LCA

Background, Goal and ScopeA complete life cycle assessment (LCA) always requires several itemizations of goal/scope definitions, inventory analysis and impact analysis. This requires the retrieval and collection of inventory information on all processes with which a product or any part of it comes into either direct or indirect contact. As a result, the data required for LCA is vast, uncertain and, therefore, complex. Up until now, unfortunately, and as far as the authors are aware, there has not been much computer-assisted aid available from any of the systems currently used in either academia or industry to support any life cycle (LC) related data representation, other than the traditional methods of tables, xy-graphs, bar charts, pie charts and various 3-D variants of those which are difficult for humans to interpret.Main FeaturesBenefiting from the synergy of latest developments in both visualization techniques and computer technology, the authors are able to introduce a new information representation approach based on glyphs. These exploit the human perceptual capability for distinguishing spatial structures and shapes presented in different colors and textures. Within this approach, issues of representing life cycle related information at a glance, filtering out data so as to reduce the information load, and representation of data features, such as uncertainty and estimated errors, are targeted.ResultsAdvanced information visualization, the process which transforms and maps data to a visual representation, employs the glyphs rendered here to create abstract representations of multi-dimensional data sets. Different parameters describing spatial, geometrical and retinal properties of such glyphs, and defining their position, orientation, shape, color, etc., can be used to encode more information in a comprehensible format, thus allowing multiple values to be encoded in those glyph parameters. The natural function of glyphs, linking (mapped) data within a known context with the attributes that in turn control their visualization, is believed capable of providing sufficient functionality to interactively support designers and LCA experts performing life cycle inventory (LCI) information analysis so that they can operate faster and more efficiently than at present.ConclusionsWithin this paper, the first of a small series on efficient information visualization in LCA, the motivation for and essential basic principles of the approach are introduced and discussed. With this technique, the essential characteristics of data, relationships, patterns, trends, etc. can be represented in a much better structured and compact manner, thus rendering them clearer and more meaningful. It is hoped that a continuing interest in this work combined with an improved collaboration with industrial partners will eventually provide the grounds for translating this novel approach into an efficient and reliable tool enhancing applied LCA in practice on a broader base.OutlookMore technical details of the approach and its implementation will be introduced and discussed in the following papers, and examples will be offered demonstrating its application and first experimental translation into practice.

Efficient information visualization in LCA: Application and practice

Aim, Scope and BackgroundAcquisition and analysis of huge amounts of data still pose a challenge, with few options available for solutions and support. Life cycle assessment (LCA) experts face such problems on a daily basis. However, data do not become useful until some of the information they carry is extracted, and most important, represented in a way humans can both recognize efficiently and understand and interpret as quickly as possible. Unfortunately, information representation techniques as used in this field are still based on traditional low-dimensional information spaces, featuring only a few basic choices to represent life cycle (LC) related data. We must part from those traditional techniques and shift to visual representations that are easier for us to understand due to the human capability for detecting spatial structures and shapes represented in different colors and textures. Then all the advantages of modern, advanced information visualization can be applied and exploited.Main FeaturesWith the introduction of a new glyph-based information representation and visualization approach to LCA, current issues of representing LC-related information efficiently at a glance are being tackled. These new techniques support reduction of information load by providing tools to select and summarize data, assist in making explicit and transparent data feature propagation, and provide a means of representing data errors and uncertainty. In this approach the human perceptual capability for easily and quickly recognizing and understanding graphical objects in different colors and textures is exploited for the design and application of highly structured and advanced forms of multi-dimensional information representation.ResultsNow in the example presented in this paper, OM-glyphs were used to represent LCA-related information for an industrial product and its compiled life cycle inventory under conditions normal for LCA. To demonstrate the application and benefits of the approach introduced, several different visualization scenarios were computed and presented. These were illustrated with a selection of generated glyph-based displays containing spherical glyph clusters for environmental items such as air pollutants and water pollutants, and inventory glyph matrices related to components and to LC phases. Where appropriate, to further aid understanding and clarity, displays were additionally shown with various orientations and in enlarged form. This is a functional feature of interactive 3D OM-glyph based information visualization that can be used in practice to efficiently navigate through displays while at the same time adjusting rendered scenes to the needs of the user at any given time. Due to the huge amount of data acquired and compiled, only a small fraction of the glyph-based displays could be shown, and, in consequence, only a fraction of the data properties, patterns and features available could be discussed in detail. However, it is believed that the basic principles and methods of this approach, as shown in a real application, could be clearly conveyed, and, most important, that the benefits and potential could be displayed in a convincing manner. This technology will support a marked increase in efficiency, speed and quality in LC information analysis.ConclusionsThis paper concludes our short series on efficient information visualization in LCA. A new approach to efficient information visualization has been introduced, together with its basic principles. This background was enriched with discussions on and further insights into technical details of the approach and the framework developed. The first practical examples were provided in the previous paper, demonstrating the mapping of LCA-related data and their contexts to glyph parameters. In this paper the application of the approach was presented using data for an actual industrial product. During the discussions, and with the various glyph-based displays shown, it could be convincingly demonstrated that all data features, trends, patterns, relationships, and data imperfections detected and examined, and sometimes traced, could be quickly and efficiently recognized in a short time. Even basic data features, such as small gaps in the data propagation of related values, could be easily seen using OM-glyphs. In the case of traditional data representation, using for example LCI tables, this would require the identification and comparison of several thousand numerical entries. As is the case with all new technology, however, it is still difficult to obtain the interest of the experts, and to convince them that such new ideas will eventually change the face of industry.OutlookA new, advanced and efficient information representation and visualization approach has been introduced to the LCA community. Hopefully, through this small series of papers, some interest will have been generated in the field of advanced information visualization. For the first time this area has been related to LCA, and some seeds for interdisciplinary research may have been sown. Now it is up to individuals, the experts in the various fields elated to those issues, to respond. The desired results will be stimulating discussions, an exchange of ideas, further initiated multilateral, interdisciplinary efforts, and improved collaboration between partners from academia and industry. At that point, efficient information visualization will finally have arrived at, and received, its deserved place within LCA.

Efficient information visualization in LCA: approach and examples

Aim, Scope and BackgroundThe data-intensive nature of life cycle assessment (LCA), even for non-complex products, quickly leads to the utilization of various methods of representing the data in forms other than written characters. Up until now, traditional representations of life cycle inventory (LCI) data and environmental impact analysis (EIA) results have usually been based on 2D and 3D variants of simple tables, bar charts, pie charts and x/y graphs. However, these representation methods do not sufficiently address aspects such as representation of life cycle inventory information at a glance, filtering out data while summarizing the filtered data (so as to reduce the information load), and representation of data errors and uncertainty.Main FeaturesThis new information representation approach with its glyph-based visualization method addresses the specific problems outlined above, encountered when analyzing LCA and EIA related information. In particular, support for multi-dimensional information representation, reduction of information load, and explicit data feature propagation are provided on an interactive, computer-aided basis.ResultsThree-dimensional, interactive geometric objects, so called OM-glyphs, were used in the visualization method introduced, to represent LCA-related information in a multi-dimensional information space. This representation is defined by control parameters, which in turn represent spatial, geometric and retinal properties of glyphs and glyph formations. All relevant analysis scenarios allowed and valid can be visualized. These consist of combinations of items for the material and energy inventories, environmental items, life cycle phases and products, or their parts and components. Individual visualization scenarios, once computed and rendered on a computer screen, can then interactively be modified in terms of visual viewpoint, size, spatial location and detail of data represented, as needed. This helps to increase speed, efficiency and quality of the assessment performance, while at the same time considerably reducing mental load due to the more structured manner in which information is represented to the human expert.ConclusionsThe previous paper in this series discussed the motivation for a new approach to efficient information visualization in LCA and introduced the essential basic principles. This second paper offers more insight into and discussion on technical details and the framework developed. To provide a means for better understanding the visualization method presented, examples have been given. The main purpose of the examples, as already indicated, is to demonstrate and make transparent the mapping of LCA related data and their contexts to glyph parameters. Those glyph parameters, in turn, are used to generate a novel form of sophisticated information representation which is transparent, clear and compact, features which cannot be achieved with any traditional representation scheme.OutlookFinal technical details of this approach and its framework will be presented and discussed in the next paper. Theoretical and practical issues related to the application of this visualization method to the computed life cycle inventory data of an actual industrial product will also be discussed in this next paper.

Integrating Life Cycle Aspects within Product Family Design: An Example for SMEs

Recent concern for the environment and high competition in globalized markets pose eminent requirements to the producing industry, including small and medium sized enterprises. Envisioned goals of a eco-design combined with a drastical reduction of product development time and increase of customized features of products require new strategies and tools. One solution subject to international investigation is the development of modular products. This approach we enhance by integrating life cycle assessment. Work done in this field was concentrated on developing methods to define either a products platform architecture or relationships between product modules and documented customer needs within the design analysis of product families. Unfortunately, all of these approaches failed to include a framework to enable also the integration of life cycle assessment. Within the scope of the work described in this paper, we target fundamental problems within the design of product families regarding the integration of life cycle assessment and economic application of information technology, suitable in terms of cost and performance for small and medium sized enterprises. The application field, where first case studies were undertaken and real product models implemented was within the design of parallel-shaft speed reducers.

Overcoming Complexity and Tradition-Related Shortcomings of Enabling Technologies: Solutions for Advanced Information Displays in LCA

In practice, enabling technologies, along with digital models and computer-aided / computer-based systems, are still not sufficiently integrated to make life cycle modeling and life cycle assessment methods and technologies suitable tools for designers and engineers. For example, life cycle assessment is becoming more and more an integral tool in todays product design and design evaluation during analysis and optimization. However, approaches and tools that still feature old fashioned paradigms and structures in critical areas such as human-computer interaction and information representation are somewhat counter-productive, considering the increase of both the complexity of the problem and the quantities of data to be handled. In this paper we aim at presenting, in a transparent way, the motivations, structure, and consequences of one approach leading to solutions which overcome such obstacles. This approach also supports the application and successful translation into practice of one modern methodology which is central for the cradle-to-grave evaluation used to improve environmentally conscious products and service designs.

LCA Related Interactive Knowledge Visualisation for Product Design

The integration of LCA into today’s computer-aided product designs requires the break-down and investigation of the entire life of products and services with respect to economical and ecological impact. As this leads rapidly to a vast amount of different data that has to be stored, structured and analyzed, the necessity of providing computerized tools to support the human expert becomes apparent beyond any doubt. Especially in the stage between inventory analysis and impact assessment, an expert needs a considerable amount of (visual) aid, in order to recognize given multi-dimensional LCI related data sets and to interpret relationships between given product design parameters and their impact in each life cycle phase. Techniques in visualization provide tools for quickly and efficiently obtaining information from data. The aim of the work described in this paper is to provide an initial framework and an experimental testbed to demonstrate and analyze the generation and use of rendered glyphs the attributes of which are controlled by a selected set of mapped LCA related information. Glyphs, by their nature, allow mapped data within a known context to be linked to attributes that in turn control their visualization. This provides sufficient functionality to support designers and LCA experts interactively as they perform LCI information analysis and leads to improvements in speed and efficiency.