Topic 3 Life Cycle Assessment Methodology

LCA is a complex, scientific, deeply detailed process of breaking down all inputs that go into making a product and looking at the outputs that occur as a result. These flows are measured against many (over 90) diverse categories of the impact associated with ecosystem health – from the obvious ones to the less well-known ones.

The effectiveness of an LCA study is based on two main attributes:

  • defined goal and scope of the study (determines the depth and width of a particular LCA)
  • quality of data used for impact assessment (should be consistent, quality-assured, reflect actual industrial process chains)

LCA consists of 4 phases and is quite complicated to perform, mainly due to the datasets (data are often hard to come by). Therefore, in many cases, LCA is best left to the experts and skilled practitioners.

There are also opportunities to conduct “quick” simplified (streamlined) LCAs, but these should not be published – they are more like “back-end” calculations to aid decision-making.

Nowadays, practitioners and scientists have developed various LCA modelling software (such as SimaPro and Gabi) and helped to build a thriving knowledge bank of cause-and-effect relationships between industrial systems and the environment. Also, all this research and information helps build capacity for a thinking tool that anyone can apply to explore how products and materials impact the planet and people – it is Life Cycle Thinking.

So, there are three different types of LCA: a) Detailed LCA, b) Simplified LCA and c) Conceptual LCA – Life Cycle Thinking.

Video: Life Cycle Assessment

An introductory video focusing on the process, use and benefits of a Life Cycle Assessment

Source: Sarah Gibson

LCA Methodology – 4 iterative steps (based on a crosswise approach)

Life Cycle Assessment Framework

Subject and intended use – Purpose? To whom (and how) to impart

Functional Unit – a reference unit on which LCA is focused

System Boundary – process units (part of a product system) to be included

Data (and data quality) requirements and methods to be used

Impact categories to be investigated

Limitations or assumptions to be made

Collection and quantification of input/output data related to the system under study – FLOWS:

  • INTO (e.g. raw materials, resources, water, energy needs)
  • OUT (e.g. waste generation, by-products and/or recycled materials, pollutant emissions to air, water and soil)

(all data must be adapted to the given functional unit)

Additional information to better understand and evaluate the magnitude and significance of potential environmental impacts for the life cycle of the product under study

Selection – impaction categories, category indicators, characterisation models

Classification of data into impact categories and parameters

Characterisation, Calculation and Estimation of environmental pressures of inputs and outputs in the life cycle (normalisation, grouping and weighting)

Summarising and discussing the results of either the inventory analysis or impact assessment, or both, and evaluating them in the context of the goal and scope of the study set out at the beginning (comparison with the initial objectives)

Determining the level of confidence in the final results – performing sensitivity and uncertainty analyses, completeness and consistency checks

It is a basis for deriving:

  • conclusions
  • recommendations
  • decision-making

Results can indicate the improvement potential (e.g. they can lead to a well-grounded list of recommendations for revising product design and optimising its use in terms of environmental impacts).

Identification of key processes, limitations and pollutants

Communication of study results in a fair, complete and accurate manner

General scheme of the four phases of LCA [Adapted from ISO 14040 (2006). Environmental management—Life cycle assessment—Principles and framework. Geneva: International Organisation for Standardisation (ISO).]

Video: Life Cycle Assessment and Strategic Sustainability

 for Product Design Engineers Tutorial by sustainability strategist Leyla Acaroglu

Source: Disrupt Design

Overview of Life Cycle Assessment (LCA) as part of a strategic sustainability workflow in product design and engineering.

The video is part of a series of introductory tutorials on core concepts in strategic sustainability, including an introduction to eco-design strategies and life cycle thinking (the series developed for Atuodesk inc)

Note with the video: ISO 14044, together with ISO 14040, replaced ISO 14041, ISO 14042 and ISO 14043, which were technically revised and cancelled.