Complete life cycle assessment

Life cycle assessment (LCA) is a technique developed for evaluating and measuring the environmental impacts associated with all the stages of a product's life from cradle-to-grave.

The procedures of life cycle assessment (LCA) are part of the ISO 14000 environmental management standards, explained in ISO 14040:2006 and 14044:2006. According to those standards a life cycle assessment is carried out in four distinct phases:

Definition of the goal and scope of the study, which sets out the context of the study and explains how and to whom the results are to be communicated. This is an important step according to the standards.

Life Cycle Inventory (LCI) analysis, which involves creating an inventory of flows from and to nature for a product system. Flows include inputs of water, energy, and raw materials, and releases to air, land, and water. A flow model, typically illustrated with a flow chart, of the technical system is constructed using data on inputs and outputs. Inventory flows should cover the full range of inputs and outputs, typically aiming to account for 99% of the mass of a product, 99% of the energy used in its production and any environmentally sensitive flows.

Life cycle impact assessment, which evaluates the significance of potential environmental impacts based on the Life Cycle Inventory (LCI) analysis. It normally consists of the selection of impact categories, category indicators, and characterization models; the classification stage, where the inventory parameters are sorted and assigned to specific impact categories; and impact measurement, where the categorized LCI flows are characterized into common equivalence units that are then summed to provide an overall impact category total.

Life Cycle Interpretation, which is a systematic technique to identify, quantify, check, and evaluate information from the previous phases. The results are summarized during this phase. The outcome is a set of conclusions and recommendations for the study. Interpretation of results is not as straightforward as comparing two numbers against each other. There are several impact categories and the interpretation requires a clear understanding of how the study was conducted and the results were developed.

However, in order to be complete from the sustainability point of view an environmental analysis must be supplemented with the analysis of social impacts. United Nations Environment Programme (UNEP) has developed guidelines for social life cycle assessment of products. It is a very complicated issue as the impacts are hardly measurable and comparable against each other. Also the control of the supply chain and tracking of impacts might become difficult even when considering simple products such as clothes.

Yet, in projects this might be easier. Good project management practices require the definition of project charter mandating the planning and execution of the project as well as the acceptance criteria. It is a fairly straightforward task to include social responsibility related issues in these definitions. Also, projects are one-of-a-kind endeavours requiring the setting of planning and control mechanisms to ensure the successful execution. Contracts can quite easily be supplemented with elements related to the social aspects and the evaluation of their outcome during the life cycle of the project and the product or service it produces.