Return to Knowledge Base

What is a life cycle assessment (LCA)?

In this article we explain what a life cycle assessment is. We dive into goal and scope, inventory analysis and impact assessment, and the analytical framework.

In this article we explain what a Life Cycle Assessment (LCA) is, how it works and why you would need it. We also provide a bit of history and give you an LCA example.

An LCA assesses the environmental effects associated with a product, process, or service throughout its entire life cycle. The term ‘life cycle’ refers to the main activities of the life cycle of a product, service, or process. From the extraction of raw materials needed to make the product, the manufacturing, use and maintenance, to the final disposal or the recycling into a possible next life cycle.

An LCA is a framework to answer the question: What environmental impact does a system (e.g. product, service, process) have on the world? It is not an easy question to answer, because there are a lot of factors involved. That is why LCA offers a uniform method for measuring environmental impact. In this way, the parts where the environmental impact is large, called ‘hotspots’, can be found. The life cycle of a specific system consists of 5 phases:

  1. (Extraction of) raw materials
  2. Production
  3. Transportation
  4. Use and maintenance
  5. Waste processing and/or link to the next ‘cycle’.

Cradle to...

There are different scopes when conducting an LCA. One way of considering the environmental impact of a system is cradle-to-cradle, which revolves around circularity and thus limitation of resources (extraction and production), use (energy consumption, auxiliary materials) and disposal (waste processing). The point is that all materials used after their life in one product can be usefully used for another product without loss of quality.

End of life options

A second way is cradle-to-grave. With this scope you start with the ‘cradle’, namely the very first phase of the production of an object, such as the raw materials. Measuring the impact ends with the ‘grave’, the final stage of the product, such as the processing of the waste.

Cradle to grave cycle

With cradle-to-gate, the scope of measuring the impact ends at the factory gate, i.e., the stage before it is transported to the consumer. It is a simplified version because it excludes, among other things, the use phase and waste phase. This makes the model suitable for situations where the purpose of the LCA is to map the production chain, or when data is still missing because it concerns the development of a product. Due to the reduced complexity, the LCA can also be calculated faster and cheaper. Other models include gate-to-gate and well-to-wheel, but these are less common.

Cradle to gate

Why carry out a life cycle assessment?

The information provided by an LCA provides the opportunity to make environmentally conscious choices in the design of a product or its further use. With the aim of minimising the environmental impact. It contributes to a company’s sustainability strategy and marketing, and can be used for internal and external communication.

Conducting an LCA prevents the shifting of environmental burdens from one place to another. A decision maker gains insight into the entire system through the LCA, rather than just information about a single process. For example, product A may seem like a better choice because it produces less waste water, but because not all impacts from the system have been investigated, information is missed. Product B has less waste water, but produces more cradle-to-grave environmental impact (for example, more chemical emissions). This knowledge ultimately leads to a different choice. This generates a transparent method to support integrated decision-making.

Read more here on why an LCA is important.

How does an LCA work?

The methodology of an LCA consists of four elements and is laid down in ISO 14040 and 14044. ISO 14040 series standards, Life Cycle Assessment, address quantitative assessment methods for the assessment of the environmental aspects of a product or service in its entire life cycle stages. ISO 14044 specifies the LCA requirements and provides guidelines for life cycle assessment (LCA), divided over four phases:

1. Purpose & Scope

The purpose of an LCA is not only to collect data on the environmental impact, but also to be able to make decisions and choices based on this data. Therefore, the goal must be predetermined and the audience to whom the results are to be communicated must be taken into account.

It must also be decided against which impact categories the object is measured against, such as climate warming potential, depletion of the ozone layer, eco- or human toxicological effects or change in land use. Furthermore, the limits of the impact on the object are determined. An example; do we measure the impact of the object on a single area or type of organism and stop at the impact on workers, or also include the impact on their families in producing the process?

2. Inventory – Life Cycle Inventory Analysis (LCI)

The system’s data is collected and modelled. What inputs and outputs does the object have? Such as use of water, raw materials, transport, etc. This data comes from, for example, the gas and electricity bill or from purchase orders.

It is important in this step to look at the availability of any EPDs of raw materials and consumables. An Environmental Product Declaration (EPD) is a declaration of the environmental impact of a product that is drawn up based on an LCA. You can therefore use LCAs as input for a subsequent LCA. A critical note here is that the presence of an EPD does not necessarily mean that this product is also environmentally friendly.

3. Life Cycle Impact Assessment (LCIA)

In the third phase, the contribution of the system's data to the various impact categories is assessed. So how does the collected data, for example transport to the factory, contribute to the warming potential of our planet?

4. Interpretation

Interpretation of the results is done via ISO 14040:2006 and includes:

  • Identifying key issues based on the LCI and LCIA phase.
  • An evaluation of the research itself: consistent, careful and complete?
  • Conclusions, recommendations, and limitations.

The interpretation is based on the values of the clients and the values of the stakeholders. The identification of stakeholders has already been set up in the first phase. Secondly, you ask which stakeholders determine what level of impact and how much is acceptable. It depends on the stakeholder whether something is labelled environmentally friendly or not.

The interpretation of the results ultimately leads to action. Because the hotspots of the system have become transparent, it is now possible to start working on making it more sustainable. This can be done in various forms, such as product development, strategy development or a marketing plan.

History of LCA

LCA is not a new concept. It dates back to 1960 when producers wanted to reduce costs and started looking into different materials, mainly for packaging purposes. Because when you save resources, you also save costs. About twenty years later, it gradually became more important to include the total cycle of the product in the analysis. Because the environmental impact is often not in the use of the product, but in the production, transport and the final phase. Furthermore, regulations on sustainability increase more and more, for all sectors globally.

Over the years, an LCA has become a standardised method for determining the environmental impact of an object. Criticism of LCA is that it contains no social impact. Currently, there are ways to map the social impact of systems as well.


Difference compared to a carbon footprint

A carbon footprint is an inventory of all the organisation’s greenhouse gases expressed in CO2, using ISO 14064. It is a calculation of the company’s total greenhouse gas emissions for the past year. The difference with an LCA is that the carbon footprint measures the environmental impact based on a single impact category, namely greenhouse gas emissions. Unlike an LCA, other impact categories such as soil pollution and land use are not taken into account.

LCA example

A simple example of what can be done with the data from an LCA is the substantiation for the choice between different mmaterials. This will influence the design of a product.


A company Hedgehog Company helped with an LCA is UNBEGUN. We made an LCA for their new product line with a cradle-to-grave scope. UNBEGUN has a collection of laptop covers and bags made from old trailer tarpaulins. The purpose of the LCA was discussed in advance with UNBEGUN, in this case to provide insight into how much CO2 UNBEGUN saves by using old trailer tarpaulins. During the inventory, data were collected on, among other things, the number of products per month, transport of the products, packaging material and also the product itself (zipper, rubber logo, etc.). In the third phase, the contribution is made by the inputs and outputs to the impact categories, for example the contribution to acidification. From the calculations of this LCA, it could be interpreted that the use of the sails saves 61,800 kilograms of CO2 equivalents, which means that the laptop sleeve has almost 20% less CO2 emissions than an average laptop sleeve.

Read the article on why you'd want an LCA
Read articleRead articleRead articleRead article
This article is written by:
Send emailLinkedInBook a meeting

We are here to guide you

We're the first generation educated as sustainability experts. We've helped many organisations with our tailor-made solutions, calculations and research.

About us