This article was written by Vivek Arulnathan. Vivek is a PhD student at the Food Systems PRISM Lab at University of British Columbia Okanagan. He currently focuses on developing a lifecycle-based, regionalised, online sustainability measurement and management platform for Canadian egg farmers called NEST- The National Environmental Sustainability Tool. Vivek’s larger goal is to see sustainability and sustainability assessment practices that prioritize the environment, society, and economics in that order. 


Life Cycle Thinking is a systems-based, sustainability management approach that considers all the relevant interactions in the supply chain associated with a good, service, activity or entity. Life Cycle Thinking is about going beyond the traditional focus on specific sustainability issues associated with individual production sites and manufacturing processes to include environmental, social and economic impacts of a product over its entire life cycle. So what is a product’s life cycle?

What is Lifecycle Analysis

The life cycle of a product begins with raw material extraction and energy generation. These materials and energy are used in the production of goods that are subsequently transported, used, recycled, reused and/or disposed of.  

Lifecycle analysis steel

What is the life, death, and reincarnation of steel? An example of Lifecycle analysis (Credit: Worldsteel)

According to UNEP, life cycle thinking helps “…recognize how our choices influence what happens at each of the life cycle stages so we can balance trade-offs and positively impact the economy, the environment, and society…” A life cycle approach identifies both opportunities for positive changes (opportunities) and negative impacts (risks) of a product, process or system. A Life Cycle Approach promotes informed selection among alternatives, awareness that our selections are not isolated, making choices for the long term, and improving entire systems and not just processes. 

Environmental Life Cycle Assessment (LCA), commonly referred to as LCA, is the most widely used methodology based on Life Cycle Thinking. LCA is the “compilation and evaluation of the inputs, outputs and the potential environmental impacts of a product system throughout its life cycle”. Simply put, it is a method to quantitatively assess the environmental impacts products and production systems from the “cradle” to the “grave”, and are primarily intended for comparative assessments. 

The Four Phases of LCA

LCA has been standardised by the International Organization for Standardization in the ISO 14040:2006 and ISO 14044:2006 standards. Together they describe the principles, framework (see figure), requirements and guidelines for a LCA. LCAs are carried out in four phases. The first phase – Goal and scope definition – is where all the choices that shape the LCA are made, articulated and clearly justified. 

The second phase – Inventory Analysis – is a technical, data-based process that results in ‘snapshot’ of all relevant input and output flows for a  system. It is the phase where the system(s) being studied are defined and modelled. 

The Impact Assessment is the third phase of a LCA and is used to understand and evaluate the magnitude and significance of potential environmental impacts of the product system being studied. The data from the inventory phase are processed and interpreted in terms of environmental impacts in this phase. Interpretation is the final phase of a LCA. The findings of the inventory and impact assessment phases are evaluated in relation to the defined goal and scope of the study in order to reach conclusions and recommendations.

LCA framework ISO 14040

Phases of LCA, as per ISO 14040, the phases of LCA are iterative and repetitive (Credit: International Organisation for Standardization)

Despite its aim to be a holistic assessment tool, the nature of LCA often necessitates simplification of some aspects of the systems considered. It is by no means a perfect framework and faces several challenges. 

To begin with, any LCA is only as good as the methodological choices made by the practitioner. LCAs of the same product can be done at different scales, with different system boundaries, and different methods of allocating resources. As a result, comparison of LCA results is often not straightforward. LCA has also historically been challenged in addressing localised impacts.

Other challenges include the linearity of LCA modelling, lack of focus on the socio-economic characteristics of product systems, data unavailability and uncertainties associated with data and modelling. However, the LCA community has, and continues to make, huge strides in addressing each of these challenges. 

Tackling the socio-economic aspects of LCA

Sustainability is of course not just about the environment. It is a more complex issue that also includes socio-economic factors. LCA has responded to this by integrating cost assessments and Social LCA into an overarching framework called Life Cycle Sustainability Assessment (LCSA). Unlike LCA, life cycle cost assessment and social LCA are not standardized methodologies yet, given their recent evolution. The standardization of these methods, especially Social LCA, on par with environmental LCA will go a long way in establishing LCSA as a robust sustainability assessment methodology. 

Reaching a stage where environmental, social and economic dimensions of sustainability can be comprehensively and consistently analysed will not be a cakewalk. Nevertheless, accomplishing this will be hugely beneficial to both science and society by ensuring holistic assessments of human actions.

As the world tackles an existential crisis in the form of climate change, life cycle thinking, LCA and LCSA will assume even greater prominence. Any carbon footprints or any report on the contributions of specific industries to climate change is most likely the results of life cycle assessments. Determining anthropogenic GHG emissions has been at the core of our understanding of global climate change. Only by adopting life cycle thinking can we ensure that practices implemented to reduce emissions do not result in increased impacts in another part of the global system. But GHG emissions aren’t the only environmental issue facing humanity. Using methods such as LCA and LCSA will also help account for other environmental and socio-economic impacts, in addition to climate change.


LCA analysis pyramid

The pyramid of life cycle analysis as it complexifies (Credit: Jgsee Kmutt University)


References used in this article

Guinée, J.B., Heijungs, R., Huppes, G., Kleijn, R., de Koning, A., van Oers, L., Wegener Sleeswijk, A., Suh, S., Udo de Haes, H. a., de Bruijn, H., van Duin, R., Huijbregts, M. a. J., Gorrée, M., 2001. Life Cycle Assessment: An Operational Guide to the ISO Standards, The Netherlands: Ministry of ….

ISO, 2006. Environmental management — Life cycle assessment — Requirements and guilelines, ISO 14044.

Pelletier, N., 2015. Life Cycle Thinking, Measurement and Management for Food System Sustainability. Environ. Sci. Technol. 49, 7515–7519.

UNEP/SETAC, 2017. What is Life Cycle Thinking? – Life Cycle Initiative [WWW Document]. URL (accessed 12.10.18).

UNEP, 2004. Why Take A Life Cycle Approach?, United Nations Environment Publication.

W Vigon,  bY B., Tolle, D.A., Cornaby, B.W., Latham Batte I le Columbus, H.C., Harrison, C.L., Boguski, T.L., Hunt, R.G., Sellers, J.D., 1993. LIFE-CYCLE ASSESSMENT= INVENTORY GUIDELINES AND PRINCIPLES.