Life Cycle Assessment (LCA): 4 Phases, Importance, Limitations

A Life Cycle Assessment (LCA) is a method used to evaluate the environmental impact of a product or service throughout its entire life cycle.
Environmental concerns are becoming more and more significant in decision-making processes across all levels, including political, economic, industrial, and individual.
important to understand the meaning behind these concepts.

Life Cycle Assessment (LCA)
Life Cycle Assessment (LCA)

It is significantly more difficult to take action. In order to achieve a sustainable future, it is crucial to not only make statements and conduct studies, but also to take meaningful actions that effectively reduce environmental impact and potentially even improve the current situation. In order for an action to be efficient, three conditions must be met:

  • It is necessary for technological solutions to be readily accessible.
  • Prioritizing various solutions and selecting the best practices should take into account environmental efficiency, cost, and economic constraints.
  • Actions ought to be optimized in order to further minimize their impacts.

What is Life cycle Assessment (LCA)?

A Life Cycle Assessment (LCA) is a methodical analysis of the possible environmental effects of products or services throughout their complete life cycle.

In a Life Cycle Assessment (LCA), the environmental impacts of a product or service are evaluated throughout its entire life cycle, including the production, distribution, use, and end-of-life phases. This encompasses both the upstream processes, such as those involving suppliers and the downstream processes, such as those involving waste management. These processes are associated with the production of raw, auxiliary, and operating materials, as well as the use and disposal phases, which may involve waste incineration.

Life cycle impact assessment (LCIA) encompasses all pertinent environmental inputs such as ores, crude oil, water, land use, and emissions into the air, water, and soil, including carbon dioxide and nitrogen oxides.

Environmental Life Cycle Assessment

There are multiple types of LCA available, but they all serve the same purpose of evaluating the environmental impact of a product, service, or material. Researchers consider them to be the closest thing to a gold standard for comprehending the environmental impacts of a product. The Life Cycle Assessment (LCA) is a widely accepted and standardized approach for quantitatively evaluating the environmental impacts of a product or process.

In essence, an LCA focuses on the extraction of raw materials and energy from the environment, as well as the environmental impact that a product, service, or material has during its use. The term “life cycle” is used because it encompasses the entire lifespan of a product. This includes the raw material stage when the product is being assembled, the usage phase when the product serves its intended purpose, and the end-of-life stage when the product is dismantled in whatever manner is appropriate.

Four phases of a Life Cycle Assessment (LCA)

The Life Cycle Assessment (LCA) typically comprises four stages or components in general.

  1. Goal and scope
  2. Inventory
  3. Impact assessment
  4. Improvement assessment
Four phases of a Life Cycle Assessment (LCA)
Four phases of a Life Cycle Assessment (LCA)
Image source:

Goal and Scope of LCA

The goal and scope of a Life Cycle Assessment (LCA) should be clearly defined in order to ensure that the study is focused and relevant. The study’s scope is determined at the stage where all decisions are made regarding its purpose, the “functional unit” being studied, the systems to be investigated, and the boundaries. It may not always be feasible or necessary to measure every input and output, especially if they are insignificant or outside the study’s scope. In such cases, they are excluded. Each LCA has its own set of boundaries.

At this stage, it is important to inquire about the necessary data, the required level of data quality, the methods to be employed for impact assessment and interpretation, as well as the reporting approach. Another task involves “screening”, which refers to the initial implementation of the LCA and any necessary adjustments to the plan.


Each LCA possesses an inventory. These are the data you’re accumulating. The inventory comprises emissions, energy requirements, and material flows for each process involved. These are the inflows and outflows of the system under study. The data for these can be adjusted based on the specific functional unit being considered.

This is commonly referred to as a Life Cycle Inventory (LCI).

The complexity of this task can be significant as it may entail numerous distinct processes and the tracking of hundreds of substances. The majority of the complexity in an LCA is concentrated in this area.

Impact Assessment

The Life Cycle Impact Assessment (LCIA) is the process of calculating the environmental impacts. The impact categories are selected, and an evaluation is conducted on the impacts they incur based on the emission, energy, and material flow from the inventory.

This stage takes into account all the chosen impacts, which may include depletion of abiotic resources, global warming, ozone layer depletion, acidification, and others.

Improvement Assessment

The results are analyzed in the context of the study’s goal and scope, as established at the outset. What insights have we gained about the system based on the results of this LCA? This is the section where recommendations are usually provided.

Stages of Life Cycle Assessment

  • Materials Extraction
  • Processing and manufacturing of raw materials
  • Distribution of Products
  • Use and Operation
  • Disposal
Stages of Life Cycle Assessment
Stages of Life Cycle Assessment
[Image source:]

Materials Extraction

Before a product can be made, the raw materials needed to make it must be extracted. There may be several environmental effects from this extraction. Mining operations are frequently needed for the extraction of materials, which wreaks havoc on the environment. Additionally, there are linked carbon emissions from extraction processes.

Processing and manufacturing of raw materials

In this phase, materials are transported to factories and processed into finished goods. It’s possible for the procedures used to make items to emit significant amounts of carbon dioxide as well as other chemical or material waste. This waste needs to be disposed of since it poses a risk to public health and the environment.

Distribution of Products

Once goods are produced, they must be made available for use and sale. During this stage, transportation is mostly responsible for carbon emissions.

Use and Operation

When certain things, like automobiles, are used, carbon emissions are produced. By increasing demand for the use of fossil fuels in the production of electricity, electrical items will also indirectly contribute to emissions. Other goods including food and drink, household cleaners, and cosmetics could generate waste in the form of packaging and chemical waste.


After a product has used up all of its useful life, it must be disposed of. This can be accomplished in a variety of ways, such as recycling, incineration, and landfilling. The need for energy to power disposal techniques like recycling and incineration might result in carbon emissions. Additionally, dangerous gaseous pollutants can be created during incineration. Landfills may leak hazardous chemicals into the environment, especially into groundwater and other natural water sources.

Various factors need to be taken into account throughout the entire lifespan of a product, and conducting detailed life cycle assessments can provide an extensive understanding of these factors. The assessment of a product’s sustainability requires considering the renewability and biodegradability of the materials used, taking into account both the extraction of raw materials and the disposal of the final product.

The environmental effects of various processes as well as the products themselves can be compared by contrasting the life cycle assessments of various items.

Read Also: Metal Recycling

Characteristics of Life Cycle Assessment

The specific characteristics of LCA are as follows:

  • Life Cycle Assessment (LCA) is a methodology that specifically targets the environmental impacts of a product or service throughout its entire life cycle. When making a decision among different options, the LCA results are combined with other factors such as costs, social implications, economic performance, and technical feasibility to arrive at a final decision.
  • Life Cycle Assessment (LCA) connects the environmental impacts to the function of the system, making it easier to compare different alternatives.
  • Balances that are quantified are conducted throughout the entire life cycle of a product or service. This includes all stages from the acquisition of raw materials to the management of waste, covering the entire span from cradle to grave.
  • The Life Cycle Assessment (LCA) method takes into consideration all significant environmental concerns that are currently recognized, such as global warming, extraction of resources, effects of hazardous substances on both humans and ecosystems, and land use.
  • It is possible to conduct a partial life cycle assessment by solely examining a company’s direct activities from gate to gate. However, relying solely on this approach may not provide a comprehensive understanding of the system under consideration due to the complexities of global supply chains, which can result in biased outcomes.
  • When a company develops a product, it is crucial to consider all the activities involved in the product’s life cycle. This is important to prevent suggesting environmental improvements that only shift pollution to other stages of the life cycle.
  • Life cycle activities occur both upstream and downstream of the business, encompassing various aspects such as the extraction of materials, electricity consumption during usage, and waste management disposal.

Comparison of life cycle assessments of plastic and paper bags

Life Cycle StatePlastic BagsPaper Bags
Raw Materials Extraction Plastic bags are made from compounds that are derived from crude oil.Crude oil is a non-renewable resource.The process of extraction results in the emission of carbon.Trees are used to produce paper. Trees can be considered as a renewable resource.The act of harvesting trees has the potential to cause harm to natural environments. The process results in the emission of carbon.
Manufacturing Manufactured in factories. Manufacturing leads to carbon emissions.Manufactured in factories. Manufacturing processes result in carbon emissions.
Distribution The products are distributed through traditional shipping methods such as lorries. This also results in the emission of carbon.Distributed by traditional shipping (e.g. lorries). This again produces carbon emissions. 
UseThis item is typically used only once before being disposed of. Produces a greater amount of waste.Often used once before disposal. Generates more waste. 
DisposalPlastic is not biodegradable, which means that it will take a significant amount of time to decompose in a landfill. Plastic bags cannot be recycled and therefore cannot be utilized in the production of new bags or other items. Paper is a biodegradable material that can decompose rapidly in the environment.Paper bags are recyclable and can be repurposed to create new paper products or plastic bags.

Importance of Life Cycle Assessment

An LCA study is the quantitative basis for your sustainability strategy and helps you make tactical sustainability decisions

  • LCAs measure the amount of raw materials, energy and water consumed as well as carbon and waste generated in the manufacturing of your textiles and garment production.
  • Through this holistic view, you will be able to identify where in the life cycle of your apparel product is the most resource-, energy- and impact-intensive.
  • This helps you uncover the hotspots for product design to make improvement, for sourcing to look for alternatives, and for management to evaluate the needs to make changes in your operations or supply chains.
  • In addition, an Life Cycle Assessment study can support you to establish and optimize your sustainability goals such as carbon reduction and energy efficiency.

Results of LCA provide valuable insights that can help you innovate with purpose.

  • Assessing the supply chains of your materials can aid in identifying the materials that hold the greatest potential for creating a favorable environmental impact.
  • An LCA study enables you to compare and evaluate alternatives for products that contain a blend of multiple materials.
  • Life Cycle Assessment results provide a scientific basis for enhancing alternative fibers’ production processes, particularly those processes of alternative fibers, particularly those that are considered special.
  • Collaborating with your suppliers on research and development can be a motivating factor to enhance the environmental advantages of your innovation.

An LCA (Life Cycle Assessment) offers reliable data to support your sustainable claims.

  • In order to support the external claims you make about your products being sustainable, it is essential to have credible environmental data, especially as more regulations are being introduced to combat greenwashing.
  • To accurately assess the environmental sustainability of a product, it is essential to consider the energy consumption and emissions produced throughout its entire life cycle.
  • An Life Cycle Assessment study provides environmental data that not only validates and strengthens your sustainability credentials but also enhances your credibility with stakeholders and customers.

LCA can boost your brand’s worth and provide a competitive edge in the fashion industry

  • Conducting a Life Cycle Assessment (LCA) demonstrates that your brand possesses authenticity, integrity, and credibility within the realm of sustainable fashion.
  • Being transparent with data sets your brand apart from others.
  • By utilizing Life Cycle Assessment, you can obtain reliable supply chain data that can effectively communicate the positive environmental aspects of your products.
  • This will enhance your product pitch to retailers and establish trust with them.

An LCA (Life Cycle Assessment) allows you to establish collaborative relationships with your suppliers and partners.

  • Collaboration between brands and suppliers is necessary for conducting LCA studies.
  • To perform an LCA, brands require various inputs from every stage of their supply chains. Acquiring this data can prove to be challenging in the absence of robust relationships with your suppliers.
  • Engaging in this process with suppliers can enhance the relationship and promote a collaborative partnership.
  • LCA studies are crucial in promoting transparency of supply chains within the fashion industry.

An LCA (Life Cycle Assessment) enables a more significant and valuable connection with your customers

  • LCA studies assist brands in educating their internal teams about supply chains and product sustainability from a life cycle perspective.
  • LCA can be used to create green storytelling about the positive impacts your products make and help communicate your sustainability achievements to consumers and retailers as well. Incorporating transparency into your brand’s values can help establish trust with both consumers and stakeholders.
  • Providing consumers with specific data that demonstrates the environmental benefits of your products can help them understand why choosing your products is the right decision.

Limitations of Life Cycle Assessment

Life Cycle Assessment (LCA) has certain limitations that can create skepticism about the accuracy of its results. Life Cycle Assessment (LCA) studies rely on assumptions and scenarios since they evaluate the real world using a simplified model. Studies may have varying scopes, resulting in the exclusion of certain impacts or processes that are included in other studies. Performing an LCA study is a resource-intensive task, primarily because of the significant amount of data required. Insufficient data collection or inadequate availability of data can result in inconclusive findings from the study.

Let us discuss on some of the drawbacks of Life Cycle Assessment

Ensuring the quality and availability of data

  • Obtaining reliable and representative data for the inventory and impact factors is a crucial challenge in LCA impact assessment. The quality and availability of data are influenced by various factors, including the scope, system boundaries, data sources, data collection methods, and data validation procedures. Inaccurate data quality and limited availability can result in uncertainties, inaccuracies, and prejudices in the outcomes of your LCA.
  • It is important to check the quality indicators of data, including completeness, consistency, accuracy, transparency, and relevance. Additionally, it is necessary to use suitable methods to manage data gaps and variability.

Categories of impact and their corresponding indicators

  • One of the challenges in LCA impact assessment is to carefully choose and define the impact categories and indicators that are pertinent and significant to achieve your intended goal and scope.
  • Impact categories refer to the specific environmental issues that need to be evaluated, such as climate change, acidification, or human health. Impact indicators are metrics that quantify potential impacts, such as global warming potential, acidification potential, or disability-adjusted life years.
  • Various methods and models exist for calculating impact indicators, each based on different assumptions, value choices, and scientific uncertainties.
  • It is important to justify your selection of impact categories and indicators, and to acknowledge the limitations and uncertainties of impact assessment methods and models.

Normalization and weighting are two important concepts in data analysis.

  • One of the additional challenges in LCA impact assessment is to effectively interpret and communicate the results in a way that is understandable and relevant. Normalization and weighting are two optional steps that can assist you in achieving that goal. Normalization refers to the procedure of expressing impact indicators in relation to a reference value, such as the average impact per person or per area. Weighting involves assigning varying degrees of importance or preference to impact categories, taking into account ethical, social, or political considerations.
  • Normalization and weighting methods can introduce further uncertainties and value judgments into the results of your LCA. It is important to maintain transparency regarding the techniques and presumptions employed for normalization and weighting. Additionally, it is advisable to refrain from oversimplifying or making broad generalizations about the outcomes.

Spatial and temporal differentiation refers to the variation or diversity in space and time.

  • One of the challenges in conducting LCA impact assessments is to accurately consider the spatial and temporal variations of environmental impacts.
  • Spatial differentiation refers to the process of taking into account the unique characteristics of both the emissions and the receptors based on their location, such as the geography, climate, or population density.
  • Temporal differentiation refers to the practice of taking into account the time-related features of emissions and their effects, such as the rate of emission, the rate of degradation, and the time frame involved.
  • Incorporating spatial and temporal differentiation into your LCA can enhance the precision and significance of your results. However, it also necessitates a greater amount of data and complexity.
  • It is important to strike a balance between the level of detail and feasibility when conducting an LCA impact assessment. Additionally, it is crucial to utilize suitable methods and tools to manage spatial and temporal differentiation

Uncertainty and sensitivity analysis are important techniques used in various fields to evaluate the impact of uncertain inputs on the outputs of a model or system.

  • One of the last challenges in LCA impact assessment is to accurately evaluate and effectively communicate the uncertainty and sensitivity of the results obtained.
  • Uncertainty refers to the level of confidence or variability present in one’s data, methods, or models. Sensitivity refers to the extent to which variations in your data, methods, or models can affect or alter your results.
  • Undertaking uncertainty and sensitivity analysis can be beneficial in identifying the sources and effects of uncertainty and sensitivity in your LCA results. These two steps complement each other and can provide valuable information for decision-making and improvement.
  • Performing uncertainty and sensitivity analysis can be a complex task that requires additional data and increased complexity. Furthermore, interpreting and communicating the results of such analysis can be challenging.
  • It is important to utilize suitable methods and tools when conducting uncertainty and sensitivity analysis. Additionally, it is crucial to provide clear and transparent explanations when reporting the results.

Terminology Related to Life Cycle Assessment

System Boundary: The system boundary is a conceptual line that separates the system from its environment. It is an important concept in system analysis and design as it helps to clarify the system’s purpose and functionality.

Product System: The product system refers to all the activities that are associated with the functional unit within the system boundary.

Functional unit: It refers to a specific component or module within a larger system that performs a particular function or task.

Reference Flow: It refers to the process of tracking and managing the movement of goods or materials from one point to another within a supply chain. It involves the use of reference numbers or codes to identify and trace the movement of products, as well as the documentation and communication of this information between different parties involved in the supply chain.

Effective reference flow management is crucial for ensuring timely delivery, minimizing errors, and optimizing inventory levels.
The functional units’ required amount of product is expressed in physical units such as mass, energy, area, volume, or any other relevant unit. In cases where LCAs evaluate intermediate products or raw materials without a specified end use, the functional unit can be represented by the reference flow. For instance, 1 ton of metal A or chemical B can be considered as the functional unit.

Life Cycle Inventory Analysis (LCI): It is a method used to quantify the environmental impacts of a product or service throughout its entire life cycle. It involves collecting data on the inputs and outputs of each stage of the life cycle, including raw material extraction, manufacturing, transportation, use, and disposal. The data is then analyzed to identify the environmental impacts associated with each stage, such as greenhouse gas emissions, water use, and waste generation.

LCI is an important tool for businesses and policymakers to make informed decisions about the environmental sustainability of products and services. The process involves gathering and evaluating all relevant data to measure the resource and energy flows that enter and exit the product system, including emissions and other releases that cross the system boundary.

Interpretation: One of the key functions of LCA analysis is to discuss and evaluate the findings of the LCI and LCIA results in order to arrive at a conclusion. Another important function is to compare different scenarios and identify any potential areas for improvement.

Reporting: The LCA study will be documented thoroughly and transparently, in compliance with the ISO 14044 standards. A critical aspect of conducting a Life Cycle Assessment (LCA) study is to ensure conformity with the ISO 14044 requirements. This can be achieved by engaging one or more independent experts to assess and confirm adherence to these requirements.

Such an approach enhances the credibility of the study and facilitates effective communication of the study results. If a company plans to make public claims of environmental superiority over a competing product, it is necessary for the LCA study to undergo an external review by a panel of three independent experts.


  • International Standard Organisation (ISO). Environmental management – Life cycle assessment: Principles and framework. ISO 14040. (2006).
  • International Standard Organisation (ISO). Environmental management – Life cycle assessment: Requirements and Guidelines. ISO 14044. (2006).
  • Maastricht University organises an online LCA course: “Life Cycle Assessment: Basic Principles and Uses”,, developed and implemented within the framework of Chemelot InSciTe, with support of the Province of Limburg, the Netherlands
  • Ciambrone, D. F. (1997). Environmental Life Cycle Analysis. Boca Raton, FL: CRC Press. ISBN 1-56670-214-3.
  • Horne,Ralph., et al. “LCA: Principles, Practice and Prospects”. CSIRO Publishing,Victoria, Australia, 2009., ISBN 0-643-09452-0
  • Vallero, Daniel A. and Brasier, Chris (2008), “Sustainable Design: The Science of Sustainability and Green Engineering”, John Wiley and Sons, Inc., Hoboken, NJ, ISBN 0470130628. 350 pages.

About Author

Photo of author

Jyoti Bashyal

Jyoti Bashyal, a graduate of the Central Department of Chemistry, is an avid explorer of the molecular realm. Fueled by her fascination with chemical reactions and natural compounds, she navigates her field's complexities with precision and passion. Outside the lab, Jyoti is dedicated to making science accessible to all. She aspires to deepen audiences' understanding of the wonders of various scientific subjects and their impact on the world by sharing them with a wide range of readers through her writing.

Leave a Comment