Life Cycle Assessment (LCA) explained

So, you have heard about life cycle assessment and how beneficial it is for sustainability in business. But how does that works exactly? This guide will give you an overview of how life cycle assessment works and why it’s the tool of choice for informed change-makers.

What is a life cycle assessment (LCA)?

Life cycle assessment (LCA), sometimes referred to as life cycle analysis, measures the impacts on the environment associated with the life cycle of a product, process, or service. Every part of a product’s life cycle – extraction of materials from the environment, the production of the product, the use phase and what happens to the product after it is no longer used – can have an impact on the environment in many ways. These parts of a product’s life cycle are called life cycle stages. With LCA, you can evaluate the environmental impacts of your product or service from the very first life cycle stage to the very last or to any life cycle stage in between.

Life cycle assessment stages
The product life cycle stages.

Life cycle studies can be performed for various scopes: cradle to gate (raw materials until factory gate), gate to gate (only focusing on the manufacturing processes) or cradle to grave (raw materials until disposal).

Why perform an LCA?

There are many benefits to LCA. Your LCA results can help you improve your product development, marketing, strategic planning and even policymaking. For example, product designers can explore how their design choices affect the sustainability of the products. Policy-makers can make decisions by comparing all major environmental impacts. Sustainability managers can assess the portfolio and see what’s needed to achieve carbon footprint goals. Marketing teams can get factual data for sustainability communications. A purchasing department can learn which suppliers have the most sustainable products and methods.

Types of LCA

Many types of LCA exist. A rule of thumb is that the more detail you want, the more complete your LCA needs to be. A report for internal use (for example, a screening LCA) has fewer requirements than a report that will be used for marketing or other external communication (ISO-compliant LCA, more on this later). There are also many LCA-related assessments, such as:

The interesting thing about a life cycle model is that you can use it to perform a variety of assessments; whatever matches your business needs right now.

Four steps of life cycle assessment

LCA is a standardized methodology, which makes it reliable and transparent. The International Organization for Standardization (ISO) provides standards for LCA in ISO 14040 and 14044. These standards describe the four main phases of an LCA:

  1. Goal and scope definition
  2. Inventory analysis
  3. Impact assessment
  4. Interpretation

LCA is an iterative methodology, where you refine things as you go along. For instance, the first round of analysis may tell you that you need more data. Or the results of the assessment or your interpretation may nudge you to revise your goal and scope. In this sense, every LCA you do not only gives you valuable advice to make changes in your business but also tells you how to best plan your next LCA to learn even more.

The iterative LCA methodology.

Step 1. LCA goal and scope definition

The goal and scope definition step ensures that your LCA is performed consistently.

An LCA models a product, service, or system life cycle. A model is a simplification of a complex reality. As with all simplifications, this means that the reality will be distorted in some way. The challenge for an LCA practitioner is to make sure the simplification and distortions do not influence the results too much. The best way to do this is to carefully define the goal and scope of the LCA study.

The goal and scope describe the most important choices, which are often subjective. For instance, the reason for executing the LCA, a precise definition of the product and its life cycle and a description of the system boundaries.

The system boundaries describe what is taken into the assessment and what is left out. For instance, small amounts of ingredients that contribute little to the total footprint can be left out of the scope of the study. Thus, the system boundaries exclude this.

Step 2. Inventory analysis of extractions and emissions

In the inventory analysis, you look at all the environmental inputs and outputs associated with a product or service. An example of an environmental input – something you take out of the environment to put into the product’s life cycle – is the use of raw materials and energy. Environmental outputs – which your product’s life cycle puts out into the environment – include the emission of pollutants and the waste streams for example. Together, this gives you the complete picture of the life cycle inventory (LCI). The LCI is all about collecting relevant data and modeling this data via inputs and outputs in a correct manner.

Step 3. Life cycle impact assessment (LCIA)

In the life cycle impact assessment (LCIA), you draw the conclusions that allow you to make better business decisions. You classify the environmental impacts of all processes collected and modeled in the LCI and translate them into environmental themes such as global warming or human health.

The most important choice you must make is how integrated you want the results to be. Would you like a single score to show how sustainable your product is? Or to be able to see whether your new design improves on CO2 emissions and how this impacts the land use? This usually depends on how you would like to address your audience and the ability of your audience to understand detailed results.

Step 4. Interpretation

During the interpretation phase, you check that your conclusions are well-substantiated. The ISO 14044 standard describes several checks to test whether the data and the procedures you used to support your conclusions. This way, you can share your results and improvement decisions with the world without any surprises. 

Life cycle assessment vs other approaches

While an LCA is very much based on data and captures the mind of the audience; other approaches rely more on capturing the hearts of audiences. The two most well-known life cycle approaches apart from LCA are:

  1. Cradle to cradle (materials used in production are fully reusable in the next life cycle)
  2. Circular economy (aimed at ‘closing the loop’ and preventing waste)

1. Cradle to cradle

The cradle-to-cradle certification system is about qualitative visions and storytelling. It uses qualitative criteria to judge whether a product can be certified. Criteria include material health, material reuse, renewable energy and carbon management, water stewardship and social fairness. The lowest score on these criteria becomes the product’s overall mark. In contrast to LCA, cradle to cradle does not measure whether a certified product actually has a lower overall environmental impact. So, a cradle to cradle-certified product may end up having a shifted or even increased burden.

2. Circular economy

The circular economy is an inspirational strategy for creating value for the economy, society and business while minimizing resource use and environmental impacts through reducing, reusing, and recycling. The circularity of materials is looked at with a Material Circularity Indicator (MCI). Combine both the robustness of the LCA methodology and the inspirational principles of the MCI and the circular economy and you have a holistic approach for innovation.

LCA software solution

Searching for LCA software solutions? SimaPro is our flagship product: life cycle assessment software that gives sustainability experts, product designers and decision-makers the power to gain insight into the environmental performance of products and services, to define hotspots and to drive positive change. We are proud that it is among the leading professional LCA software packages – used by industries, consultancies, and research institutes in more than 80 countries.

With SimaPro, you can:

  • Easily model and analyze complex life cycles in a systematic and transparent way.
  • Measure the environmental impact of your products and services across all life cycle stages.
  • Identify the hotspots in every link of your supply chain, from the extraction of raw materials to manufacturing, distribution, use, and disposal.


Do you want to use the LCA methodology to reach your environmental business goals? Explore our services and let our consultants help you get started!

Laura Golsteijn

Senior Consultant

I am eager to increase the environmental awareness of our society, and I believe that everyone can contribute to a more sustainable world, every day. At PRé we provide companies with both the knowledge and the tools to improve their products and services. I am excited to work for an organisation that is involved in developing sustainable initiatives.

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