The Life Cycle Inventory Analysis (LCI) looks at the environmental inputs and outputs of a product or service. It is essentially the data collection phase of our LCA.
Look at it as buckets:
In phase 1, we defined the buckets we want to put our data in, in phase 2 we fill the buckets.
The goal is to quantify the environmental inputs and outputs – this means we measure everything that flows in and out of the system we defined in phase 1.
What could these inputs and outputs be?
– Raw materials or resources
– Different types of energy
– Emissions to air, land or water by substance
Now, this analysis can be extremely complex – because production processes and the supply chain can be extremely complex constructs.
This is why the Life Cycle Inventory phase of the Life Cycle Assessment can take not only a large amount of time but also often be the most work within an LCA.
How is the data for the Life Cycle Inventory collected?
Life Cycle Assessments today are conducted by professionals who are extensively trained in the norms and standards that define how an LCA should look like. We will look deeper into these standards later in this guide. However, with software solutions like our Environmental Intelligence platform, everybody can perform an LCA.
A lot of the data for the LCA is already available – for example in your electricity or water bills. But that’s of course not all the data we need.
This is why, at this stage, the data gets collected through data collection sheets. These sheets gather quantitative data on a company level, process level and product level. If qualitative data is needed, questionnaires might be used. The data sheets get filled out by the stakeholders in the company who have access to the data.
Sometimes, industry averages have to be used.
One method for that would be the Economic input-output life cycle assessment we described earlier, which can give us data to fill some blanks. Other times, the averages could be aggregated data gathered by branch organizations, financial institutes, NGOs or market research organizations.
Modeling the LCI: Inventory Flow Models
Collecting the input and output data within a list or table would quickly lead to confusion.
Moreover, it would also lead to important context going missing.
That is why the Life Cycle Inventory is typically illustrated with a flow model.