ökobilanz life cycle assessment LCA Definition
Life Cycle Assessment - definition & methodology

A life cycle assessment or analysis according to ISO 14040/14044 is an instrument of environmental and sustainability management. Its aim is a comprehensive analysis of the environmental impact of products and services

LCA for product sustainability

What is Life Cycle Assessment?

A Life Cycle Assessment (LCA or Life Cycle Analysis) is a method to assess and analyze the environmental impact of a product over its entire life-cycle. In this context, the term 'product' also includes services.

The analysis of the entire product life-cycle – from resource extraction to production, use, and disposal – guarantees an integrated evaluation of all inputs and outputs, thus making sure negative environmental impacts and emissions aren't shifted to other life cycle phases of the product.

The methodology is defined in the ISO 14040/14044 standard. For the analysis of the environmental impact data from all materials, resources and energy used should be included.

In literature and practice, there are various forms of life-cycle analysis, differing in scope, objective and products considered. All forms are subject to the same principles and methodologies, which are presented below.

Different types of environmental assessments

Screening LCA

Rough estimation and assessment of environmental impacts considering the most relevant materials and resources using average data.

Product LCA

Descriptive analysis of the environmental performance of an individual product over its entire life cycle.

Comparative LCA

Comparison of different products or product variants. Different processes and production systems can also be compared.

Life Cycle Assessment Definition

Goals of an LCA

A Life cycle analysis of a product pursues various objectives:

  • Acquisition of environmental information & integration of ecological knowledge
  • Identification of optimization potentials of the environmental performance
  • Reduction of materials used & environmental impacts
  • Creation of sustainable products
  • Combining economic and environmental advantages

Setup of an LCA

An LCA is carried out in accordance with the standards ISO 14040/14044 in 4 steps:

  • Definition of objectives, system boundaries and scopes: Which products are analyzed and compared under which conditions?
  • Life Cycle Inventory: Which material & energy is used and emissions occur during the life cycle of the product?
  • Impact assessment: How are the results of the Life Cycle Inventory assessed with regard to their environmental impacts?
  • Interpretation: How are the results of the Life Cycle Inventory and impact assessment interpreted?

Life-cycle phases

A holistic LCA considers the entire life cycle of a product (cradle-to-grave). This is roughly divided into the following 5 main phases or stages:

  • Raw material
  • Manufacture
  • Distribution
  • Consumer use
  • Disposal/recycling

So in addition to the production system, further upstream and downstream process steps are evaluated.

Environmental impact categories

In general, all relevant potential harmful effects on soil, air and water must be taken into account through the use of resources and materials on the one hand and the emissions of pollutants on the other.

The ISO 14044 standard describes a large number of possible environmental impacts. The best known are:

  • Global warming potential / Carbon Footprint (GWP)
  • Acidification potential (AP)
  • Eutrophication potential (EP)
  • Human toxicity
Life Cycle Assessment Definition

Aggregation and valuation (LCIA) methods

A major challenge in a life cycle assessment is to summarise the various environmental impacts (e.g. greenhouse effect or eutrophication). There are different evaluation methods (life cycle impact assessment methods), which differ in the procedure, e.g. with regard to weighting.

Some methods only consider a selected environmental area, such as the cumulative energy demand or the carbon footprint. Other fully aggregating methods (such as the Eco-Indicator) combine various environmental impacts into a single key figure.

The decisive factor for the selection of suitable impact categories and assessment methods should always be the product analyzed and the respective facts.

    Examples of LCIA methods

    • CML2001
    • Environmental Footprint (EF)
    • Cumulated energy demand
    • Eco-Indicator 99
    • Ecological footprint
    • Ecological scarcity method
    • Impact World+
    • Recipe 2016

    Life Cycle Assessment databases

    A large part of the effort involved in preparing an LCA is the research process of suitable data. For the production process, it is important to work with your own primary data. However, environment-related data, especially for upstream and downstream processes, are very difficult to collect. Therefore, secondary data are used for these cases:

    • LCI database: contains Life Cycle Inventory data of a product or component and the material, energy and emission flows contained therein.
    • LCA database: contains environmental data and methods for assessing the ecological impact of a product.

    > More information on frequently used (inventory) databases

    LCA Examples

    LCA – examples & case studies

    The LCA experts and environmental engineers from the Institute of Environmental IT apply this method in various projects to increase the sustainability of products, production systems and entire companies. Learn more about exciting examples from our daily work:


    LCA & Carbon Footprints Case Studies

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