LCIA Calculation & Results

This page covers the two common LCIA usage patterns in TianGong LCA:

• Viewing LCIA results directly inside a process or model
• Moving to the dedicated Process Analysis Workspace when you need comparison, grouping, or contribution-path analysis

What LCIA means here

LCIA converts life cycle inventory results into impact-category results such as climate change, acidification, or ozone depletion.

The platform currently supports both:

• Process-level LCIA results
• Model-level LCIA results

Both are useful for direct inspection. For cross-process comparison or path tracing, use the separate analysis workspace.

Before you run LCIA

Confirm the following first:

• The process or model has complete input/output modelling
• A reference flow or functional unit has been defined correctly
• You are reusing the platform's standard flow properties, unit groups, and elementary flows where possible
• The selected impact method actually contains matching characterisation factors

Heavy use of custom units, custom flow properties, or non-standard elementary flows can lead to missing results or incorrect magnitudes.

Process-level LCIA

Process-level entry point

Open a process in My Data → Processes and use the LCIA results area in the process editor or viewer.

Process-level best use cases

• Quickly checking the impact profile of one process
• Spotting abnormal impact categories during authoring
• Performing a single-process sanity check

Important limitation

Process-level LCIA mainly reflects the elementary-flow impacts associated with that process.

That means:

• It is useful for one process at a time
• It is not the same as a full product-system total
• It should not replace multi-process comparison or contribution-path analysis
• When you view process LCIA in the Open Data scope, the page prefers published LCIA result sets. These result sets are generated, previewed, and published from the Data Processing workspace by data_product_manager users, and include only inputs that satisfy published-state eligibility rules. If the related result set has not been published, is empty, or is temporarily unavailable, the page shows the corresponding empty or unavailable state.

Model-level LCIA

Model-level entry point

Open a model in My Data → Models and use the LCIA results area in the model result workspace.

Model-level best use cases

• Reviewing full product-system impacts
• Comparing alternative model setups
• Checking whether a solved model behaves as expected

Compared with process-level LCIA

When to move to Process Analysis

If your task is any of the following, the LCIA result panel is no longer enough:

• Impact comparison across multiple processes
• Grouped analysis by location, classification, dataset type, or team
• Contribution path exploration from a root process
• Switching between Current user data, Open data, and All data

In those cases, go directly to Process Analysis Workspace.

Troubleshooting

Why are some impact categories missing?

Check:

• Whether flows are linked to the correct standard flow properties
• Whether unit conversions are valid
• Whether the selected impact method contains matching factors

Why do the result magnitudes look wrong?

Common causes include:

• Incorrect unit conversion
• Custom unit groups or flow properties that do not align with platform defaults
• An incorrect reference flow or functional unit
• A product input exchange exchange.location points to a different supply region, or process annual supply / production volume changes the provider shares across multiple providers
• If the consumer process and an eligible reference-output provider for the product flow share the same model_id, the system first uses that same-model provider subset before geography-tier selection and annual-volume weighting. Providers from another model do not enter that input's supply mix only because they are geographically closer or have a larger annual volume
• Missing, invalid, or non-positive annual volume uses a default positive weight. When investigating, check snapshot coverage and provider-linking diagnostics for fallback counts and supply-region sources
• Automatic provider linking treats only a quantitative reference output as an eligible provider for that product flow. Same-flow_id non-reference outputs are recorded only as diagnostic candidates and do not automatically enter the supply mix. If diagnostics report rejected_non_reference_only, repair the reference output, add provider data, or model the market / co-product process explicitly before recalculating.

Why should I use Process Analysis instead?

If you have moved beyond reading one result and now need comparison, grouping, or tracing, continue with Process Analysis Workspace.