LCA Methodology

Life cycle assessment (LCA) is a process for analyzing the environmental impacts generated over the entire life cycle of a product from provision of raw materials to final disposal of the product.

The internationally agreed standard for LCA has been developed by the International Organisation for Standardisation (ISO), and this is documented in four environmental management system standards (the ISO 14000 series). The methodology is generally broken up into four stages¹: definition of the goal and scope; life-cycle inventory analysis; life-cycle impact assessment, and life-cycle interpretation

Why and How of LCA

Conducting a highly detailed, quantitative LCA is an extremely complex and time-consuming process. Several industry groups or national organizations have sponsored broad studies of products such as shoes, detergents, or basic materials like steel and cement.

Due to the level of resources required, however, many companies choose to either undertake qualitative LCAs to prioritize issues or they settle for approximate data results that indicate the order of magnitude of the problem.

An LCA begins with mapping the life cycle of the product, starting with the production of raw materials and moving through the various stages of production (or manufacture), use, and disposal. At each point, an inventory is created that identifies the environmental impacts caused at that stage, including both pollution emissions and resource depletion. Calculating the impacts of operations under a company's direct control (i.e. typically manufacturing or assembly of the product and perhaps distribution) is relatively straightforward. However, accurately calculating the environmental impacts at other stages in the life cycle, such as the manufacture of inputs or the use of the product, is not always possible. Such calculations require access to information about the facilities or operations of other organizations or of individual consumers that may not be available and can only be estimated.

Computer-aided Modeling

Life cycle assessment is usually considered as the basic principle for developing general guidelines to evaluate how clean is clean.  Computer-aided LCA "modeling methodology categorizes and quantifies the environmental attributes of a certain product within its life cycle into major impact groups, such as ozone depletion, greenhouse-gas emission and acid rain, etc. Parameters and indicators are defined to represent the different attributes. The LCA methodology consists of inventory analysis, impact analysis and interpretation. It is not straightforward and requires a huge number of data. It usually needs professional service to perform a good and reliable LCA study."⁴

Simplified Approach Approach to LCA During the Product Design Stage

Traditional life cycle assessment (LCA) methodologies are accurate and accepted ways of analyzing environmental burdens. However, a good LCA is time-consuming, expensive, and depends upon having clear and reliable information about the product. The new trend is towards simplified LCAs  instead of undertaking complex and detailed quantitative evaluations. It is particularly important to have a simplified LCA methodology to support decisions at the conceptual stage of product design. Decisions during the conceptual design stage have a great effect on the environment impact of the product. However, the detailed product information necessary for traditional quantitative LCA is often unavailable. A simplified LCA approach, called a learning surrogate LCA, was developed to make LCA predictions during the conceptual stages of design.³