4 main phases of LCA

There are 4 main phases of LCA:

1.    Goal and scope

An LCA starts with a clear statement 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 a key step and the ISO standards require that the goal and scope of an LCA be clearly defined and compatible with the application. 

 

2.    Life cycle inventory

Life Cycle Inventory (LCI) analysis involves creating an inventory of flows from and to nature for a product system. Inventory flows include inputs of water, energy, and raw materials, and releases to air, land, and water. To develop the inventory, a flow model of the technical system is constructed using data on inputs and outputs. The flow model is regularly illustrated with a flow chart that includes the activities that are going to be evaluate in the relevant supply chain and gives a clear picture of the technical system boundaries.

 

3.    Life Cycle impact assessment

Inventory analysis is followed by impact assessment. This phase of LCA is aimed at evaluating the importance of potential environmental impacts based on the LCI flow results. Classical life cycle impact assessment (LCIA) consists of selection of impact categories, category indicators, and characterization models, the classification stage, where the inventory factors are sorted and assigned to specific impact categories and impact measurement, where the categorized LCI flows are characterized, using one of many possible LCIA systems, into common equivalence units that are then summed to provide an overall impact category total.

4.    Interpretation

Life Cycle Interpretation is a systematic technique to identify, quantify, check, and evaluate information from the results of the life cycle inventory and/or the life cycle impact assessment. The results from the inventory analysis and impact assessment are summarized during the interpretation phase. The outcome of the interpretation phase is a set of conclusions and recommendations for the study. According to ISO 14040:2006, the interpretation should identification of importance issues based on the results of the LCI and LCIA phases of an LCA, evaluation of the study considering completeness, sensitivity and consistency checks and conclusions, limitations and recommendations.