Data collection is a foundational step in Life Cycle Assessment (LCA), ensuring the accuracy and depth of your environmental impact analysis. This guide outlines a systematic approach to gathering both primary and secondary data. This article covers the following questions:
How to collect primary data?
What to do when primary data isn’t available?
Feel like you're missing information? This article builds upon the following articles, check them out if you want to learn more:
On data types: Explained: Data in LCA
How to collect primary data?
Primary data is essential for accurately modeling the specific impacts of your product or facility’s footprint. This data generally includes material composition, transport details, and manufacturing (processing) impacts. Download our PDF guide to data collection OR follow the steps below.
Data collection downloadable guide
Download our guide to (primary) data collection here: Data Collection Downloadable Guide .pdf
Steps for primary data collection
General guidelines for data collection
The following guidelines apply to every data point you need! Keep them in mind as you follow the data collection process.
Document choices & assumptions: Record all decisions, including sources and assumptions, to justify data usage later.
Pro tip - documenting choices & assumptions: This is best done in a consolidated (Word) document that is accessible to all stakeholders. For Mobius users, alternatively, choices & assumptions can be logged using the ‘description’ field that is available for every object in your workspace.
Prioritize high-impact data: Focus on materials and processes that significantly influence your product’s environmental footprint, aiming to cover 95% of the product’s weight with precise data. Aim to use rough estimates or proxy data for the remaining 5% that is hard to collect. Below we dive deeper into the specific data that needs to be gathered.
Overestimate assumptions: When making assumptions, aim to overestimate impacts rather than underestimate them. Overestimation leads to a more conservative, robust model.
Capture basic data points: For every material, transport method, or production step, ensure you record both the amount and units of measurement used per product.
Start with what’s available: Begin by collecting what’s available, even if it’s high-level or totals for the entire facility, rather than for your declared unit. Data collection can be refined iteratively, and translated from aggregates to product-level.
Materials data collection
Step 1: Collect the Bill of Materials (BOM)
The BOM for your product lists the materials and intermediate components in the product, including their names and quantities (preferably in kilograms).
Step 1A: Find the BOM
Find the BOM for your product by checking your company’s ERP system for the latest version, asking a product specialist to help identify the BOM, and/or involving an ERP specialist to ensure you have the correct BOM data.
Step 1B: Review the BOM data
Check the following to ensure your BOM data is correct:
All components are listed with accurate weights.
The BOM version is current.
Units are in kilograms (convert if necessary).
Because of eventual waste or scrap materials generated in processing, the total BOM weight tends to be slightly greater than the final product’s weight. If there are any significant deviations, contact an ERP specialist.
Step 2: Collect material information
Once you have the BOM, gather further data on the materials to aid in selecting the correct environmental datasets later in your analysis.
Collect the following material information:
Material composition: Identify the materials the product’s components are made of (e.g., 100% recycled PET). If your product is assembled from intermediate products or components, determine what they are made of. This might involve contacting your supplier(s) for an accurate overview of the components’ compositions.
Production location: Record where the materials or components are produced. This will aid at a later stage, in determining the impact associated with upstream transport/logistics.
Production technology: Identify the method for producing the material.For in-house manufacturing, optionally collect the energy source used and the amount of energy used for processing.
Pro tip - Finding material information: Use the resources available to you! For example:
Consult product specialists or the purchasing department.
Refer to Technical Data Sheets (TDS) or Safety Data Sheets (SDS) for component materials.
Contact suppliers for missing or detailed data on key materials.
Transport data collection
Step 3: Gather supplier and transport information for each material
For every material used in your product, collect the following information:
Material supplier: Identify the supplier of the material. (You might have done this already in the previous step)
Supplier type: Determine whether they are a producer or distributor.
Transport mode: Identify the modes of transport (e.g., truck, ship, train, plane).
Supplier location: List the city and country they are based in.
Transport distance: Calculate the distance traveled for each mode of transport.
Pro tip - Transport distances: Typically we use Google Maps to determine distances traveled by road (via truck/lorry). For sea & plane logistics, find a website that can calculate the distance for you. At Ecochain, we sometimes use the following website to determine distances covered by (container) ships.
Pro tip - Transport data: Having trouble finding this transport data for every material? Use the following strategies:
Unknown source: Use Google to research common production locations for the material.
Multiple possible sources: If the material comes from different regions, assume the farthest reasonable source - a ‘worst-case approach’.
Unknown location within a country: Choose a central location within the supplier's country.
Unknown origins for minor materials: For materials under 1% of the product’s weight, use a standard distance estimate (e.g., 150 km).
Remember! Always document your assumptions! If you really can’t determine transport distances, disagree with your own assumptions, or want to save time - you can always use “market for datasets” that include a representative amount of upstream transportation to the factory. You can always come back and refine data later!
Manufacturing data collection
Step 4: Determine the data granularity level
Before collecting data, understand the granularity of your manufacturing data. This refers to how detailed your information is and will affect the time spent on data collection and the precision of your LCA model.
Identify the granularity level of your data by collaborating with production managers, data analysts, and other stakeholders.
Product level: Collect data specific to the production of a single product. This is the most detailed and preferred level. OR;
Production line level: Track data for specific production lines. OR;
Production process level: Measure data for specific production processes or machinery. OR;
Facility level: Use total data for the entire facility if more detailed data isn’t available. Total facility data can be combined with total production (mass or units) data to determine the average energy & waste per product.
Pro tip - Granularity level: It can help to scout dataset availability throughout the data collection process. For some processes, ecoinvent has ready-made datasets available (e.g. injection molding for plastics), while other, more specific, processes might not have readily-available datasets. Dataset availability, to some extent, can also determine the level of granularity required in your primary data.
Step 5: Determine whether allocation is necessary
If your factory produces multiple products that share processes, you may need to allocate the environmental impacts. Gather the following data to assist with allocation:
Physical factors: Production amount or volume of each product.
Economic factors: Sales price (for example)
Other relevant data: Information like energy costs per product.
Step 6: Collect Manufacturing data
Gather all available data, even if it's not perfectly segmented. Focus on collecting as much information as possible.
Note - Collecting manufacturing data: Focus solely on manufacturing-related impacts. Exclude:
Office Impacts: Energy and resource use for office spaces.
Employee Commuting: Environmental impact of commuting.
Employee Sustenance: Impacts related to employee welfare.
Pro tip - Finding manufacturing data sources: Leverage existing data within your organization:
ERP systems: Check for records of energy use, materials, and waste.
Other administrative systems: Look for production metrics and inventory tracking.
Financial records: Use costs related to energy, materials, and waste disposal as data points.
Step 6a: Collect Production Impact data
For each item below, gather the amount and unit per declared unit per product.
Energy impacts: Record all energy used for manufacturing (direct - e.g., electricity to power machinery) and non-production ( indirect - e.g., lighting, heating) purposes, specifying the type.
Waste: Document waste generated directly from production processes (e.g., scrap, defective products) and indirectly from the facility (e.g., packaging materials from incoming supplies). Just like energy, waste data might only be available on an aggregated level - e.g. per month. This will work, in combination with production volume data, to estimate the average waste generated per product! (see pro tip above).
Process-specific materials: Track materials directly consumed during production (e.g., lubricants, cooling water) and supporting materials (e.g., disinfectants, cleaning agents). These are known as auxiliary materials.
Internal transport fuels: If applicable, track the fuel used to transport materials within the facility.
[Optional] Step 6b: Collect Emissions data
Check if your facility emits any of the following emissions, and quantify them if you do:
Emissions to air:
Chemical reactions: Your processes release volatile organic compounds (VOCs) or other gases (e.g., painting or baking).
Emissions to water:
Discharges to water bodies: Your processes discharge wastewater directly into natural water systems (e.g., rivers or lakes).
Emissions to soil:
Soil contamination: You have emissions that seep into the soil (e.g., spills or leaks of hazardous materials).
Extractions from nature:
Resource extraction: Your manufacturing process involves directly extracting resources from the environment (e.g., drawing water from a river for cooling).
What to do when primary data isn’t available?
When primary data isn’t accessible or is less relevant (for background, environmental data), you can rely on secondary sources to complete your LCA.
Use LCI databases: Databases provide secondary data for environmental impacts (background environmental data), reflecting average values for common materials and processes within a geography. They are valuable for filling data gaps in your LCA, although results may be generalized.
Create custom datasets: If no direct dataset exists, combine relevant data points from available datasets to model similar products or scenarios (e.g., combining datasets for materials and processes for a similar product).
Consult LCA experts: Ecochain’s specialists can help design custom datasets or navigate complex modeling scenarios, especially for unique production processes like biomass gasification.
Declare data gaps: If a data gap remains, document it transparently in your assessment. Examine options to estimate impacts through proxies, adjust the scope, or follow regulatory guidance for approximation.
Next steps
Effective data collection in LCA combines primary data with informed secondary data to present a complete environmental profile of your product. Documenting assumptions, prioritizing high-impact inputs, and collaborating with suppliers ensure a robust foundation.