A Web Based Application for the Eco-PaS Tool Wim Dewulf, Joost R. Duflou Katholieke Universiteit Leuven, Mechanical Engineering Department, Belgium Abstract The Eco-PaS methodology supports anticipative weak point analysis of a product’s life cycle environmental impact. Using quantitative information available in early design stages, the order of magnitude of an environmental indicator is estimated. This result is obviously influenced by a number of uncertain factors. However, a critical analysis of these factors allows pointing the designer at promising design directions at a time in the design process when many degrees of freedom remain open. This paper recapitulates the principles of the Eco-PaS methodology, and introduces a web-based application of the Eco-PaS tool. Keywords Eco-PaS, environmental impact screening, conceptual design, web-based tool 1 INTRODUCTION The assessment of a product’s environmental profile is typically performed using Life Cycle Assessment (LCA). However, a full LCA requires the identification and quantification of the emissions, energy and material flows throughout the lifecycle of a product. Often several hundreds of processes need to be scrutinised, making LCA a very time-consuming assessment technique. In a product development context, data availability is even more problematic, since many decisions yet need to be taken. Therefore, LCA is only suited for ex-post assessment of the design process result. In order to achieve the significant data need (and cost) reductions required for ex-ante assessment, rough environmental assessment methods have been developed that are now used by a number of frontrunner companies ([1], [2]). They eliminate the extensive data gathering efforts connected to tracing all life cycle processes and their related elementary flows (emissions, waste, material and energy) by making use of average data for common sections of a product life cycle. Based on these average data, an impact assessment is performed using a standard LCA methodology (e.g. Eco- indicator'99 [3]), thus leading to e.g. indicator scores per kg of material or per kWh of electricity. Standard values are typically available for materials (per kg material), production processes (e.g. per square metre of rolled sheet or per kg of extruded plastic), transport processes (per tonne-kilometre), energy generation processes (per kWh or MJ), and disposal scenarios (per kg of material). In order to use these rough environmental impact calculation methods, the materials inventory and a list of product life cycle processes is required. The need for a detailed materials inventory however limits the applicability of the simplified LCA methods in the design process. For example, during early design phases, when only functional requirements and product concepts are available, the materials inventory is yet undefined. Nevertheless, decisions taken in the conceptual design phase can influence the outcome of a design exercise far more significantly than any optimisation step later on in the design process [4]. In an eco-design approach an early recognition of favourable system component solutions is therefore of great importance. Moreover, even for fully developed products, a detailed materials inventory is difficult to obtain when many components are bought off-the-shelf. This especially holds true for small and medium-sized enterprises, which can provide little incentives to enforce suppliers to provide the requested data. 2 THE ECO-PAS METHODOLOGY 2.1 Eco-Cost Estimating Relationships (E-CERs) As a solution to the highlighted problems, we have introduced the Eco-PaS methodology (Eco-Efficiency Parametric Screening) [5, 6, 7]. Eco-PaS makes use of Eco-cost estimating relationships (E-CERs), defined as mathematical expressions relating an eco-cost as dependent variable to one or more independent eco-cost driving variables. In this framework an eco-cost can be expressed in monetary units, such as external costs or willingness to pay, or by any other commonly used environmental performance indicator, such as, for ex- ample, the Eco-Indicator99 [3] that will be used in this paper. The eco-cost driving variables are functional requirements (FR) or design parameters (DP) that product developers have at hand when designing or selecting components from catalogues. Consequently, parametric expressions are used which express the environmental LPSDFW DVDIXQFWLRQ  I)5 '3 )RU H[DPSOH WKH cradle-to-gate Eco-,QGLFDWRUVFRUH IRUWKHSURGXFWLRQ of electric motors can be estimated based on their nominal power Pnom I3nom). The E-CERs can be derived using theoretical model development, regression analysis on empirical data and growth laws [8]. As an example, we derive the E-CER for a recipient. From a functional point of view, the major functional parameter is the amount V[m³] of gas, liquid or bulk material the recipient can contain. First consider a hollow cubical recipient with open top side and lenth b[m], hence V = b³ (1) Assuming a wall thickness t[m] and negligible production waste, one easily calculates the amount of material A[m³] needed to produce the recipient: A = 5 b² t = 5 V 0.66 t = i V 0.66 t (2) The coëfficiënt 5 in this equation is typical for open cubical volumes; Table 1 presents the shape factor i for other recipient geometries. For a material with environmental impact score i [Points/m³], Equation 2 can be rewritten as Impact score = i j V 0.66 t (3) Table 2 shows the material factor j for a selection of materials. 143