24 August 2026
How to Import a BOM Into LCA Software Without Errors
Importing a bill of materials into LCA software is not a one-click conversion from engineering data to environmental results. The reliable approach is to preserve the original BOM, map its structure and units, add the processes the BOM omits, and review every uncertain environmental dataset match.
TL;DR
Prepare the BOM around stable part identifiers, quantities, units, assembly relationships, variants, and revisions. After import, normalize units, map parts to environmental datasets, add missing life-cycle processes, and validate mass balance and duplicate counting. The uploaded file is an input to the LCA—not a completed study.
1. Understand what the BOM does—and does not—contain
An engineering BOM describes parts and assembly relationships. An LCA inventory represents material and energy flows across a defined product system. Those are related structures, but they are not interchangeable.
A BOM row might identify a steel bracket, its quantity, supplier part number, and parent assembly. The LCA model still needs an environmental dataset, geography, production process, transport assumptions, manufacturing losses, and treatment at the end of life. Depending on the study boundary, it may also require packaging, utilities, maintenance, replacements, and warehouse operations.
This distinction is visible in commercial import workflows. One Click LCA converts an Excel source into a structured review file and explicitly says the result is not a finished LCA or EPD, according to its BOM AI import documentation.
2. Prepare the source file before uploading it
Start with an untouched copy of the engineering BOM. Create a separate import file so that corrections, exclusions, and mappings do not overwrite source values.
Each row should have, where available:
- A stable part or item identifier
- A clear description
- Quantity and unit
- Material or specification
- Parent assembly or hierarchy field
- Variant, SKU, or applicability information
- Revision or version
- Supplier and manufacturing geography
- Mass per item when quantity is expressed as pieces
Minimum templates vary. One Click LCA requires at least three fields: description, quantity, and unit, while Earthster documents five mandatory field groups: cycle, component, amount, unit, and geography.
Do not silently replace missing values. Keep the original field, add a normalized field beside it, and label assumptions or proxies separately. This makes it possible to distinguish supplier data from estimates during review.
3. Preserve the assembly structure
A flat material list loses information that matters when products share subassemblies or have multiple configurations. Retain parent-child relationships, reused modules, depth levels, variants, SKUs, and revisions wherever the destination software allows it.
Earthster supports nested product structures through a depth or tree field in its import format, and its Generator can create or update product LCA models from CSV and XLSX files, as documented in the Earthster Generator guide. In Dawn, parts and assemblies can be managed with assembly versions and product changes, allowing the environmental model to follow a changing product rather than a single frozen spreadsheet.
Use separate records for a part and its use within an assembly. The part record can hold material, supplier, and dataset information; the assembly relationship holds the quantity and position in a particular product configuration. This prevents a quantity change in one variant from changing every other product that uses the same part.
4. Map columns, units, classifications, and resources
Import tools generally separate file ingestion from environmental mapping. One Click LCA documents file upload, import settings, column mapping, unit and classification review, resource mapping, and completion as separate stages in its import process.
Map identifiers and hierarchy fields before mapping environmental resources. Then standardize units without discarding the original values. Check whether “kg” means net material mass, purchased mass, or mass including expected scrap. Convert item counts to mass only when the conversion factor is documented.
Saved mappings can reduce repeated setup for files with the same schema. One Click LCA allows column mappings to be reused in later imports. Reuse is safest when the source system, export version, and column meanings have not changed.
5. Review environmental dataset matches
Automatic matching can accelerate classification, but it cannot resolve every ambiguity in a part description. “Aluminium housing” does not establish alloy, recycled content, production route, geography, finishing process, or supplier-specific performance.
Review each match for:
- Material and production-route fit
- Geographic representativeness
- Dataset age and technical relevance
- Unit compatibility
- Inclusion or exclusion of processing
- Whether supplier-specific data should replace a generic proxy
One Click LCA identifies non-material rows instead of treating every row as an environmental input. It also uses fallback values or flags uncertain cases for human review, according to its BOM import guidance. Apply the same principle regardless of software: label uncertain matches and do not hide them inside apparently complete results.
6. Add what the engineering BOM leaves out
Once materials are mapped, add the life-cycle processes required by the goal and scope. Typical omissions include inbound transport, manufacturing energy, process consumables, losses, packaging, distribution, maintenance, replacement, and end-of-life scenarios.
Athena Building LCA, for example, lets users supplement an imported building BOM with transport, replacement, and end-of-life scenarios before reporting cradle-to-grave results, according to the Athena Building LCA product page. This illustrates why material import and system modelling are separate tasks.
Document exclusions explicitly. A zero value, an excluded process, and a missing value mean different things and should not be represented by the same blank cell.
7. Validate the imported model
Before calculating results, perform structural and quantitative checks:
- Compare imported row counts with the source file.
- Check for parts counted both individually and inside an imported subassembly.
- Recalculate item-to-mass conversions.
- Compare total material mass with a known product or shipping mass.
- Review units, decimal separators, and conversion factors.
- Confirm variant and revision applicability.
- Inspect every proxy, fallback, exclusion, and uncertain match.
- Confirm that geography and dataset choice are appropriate.
Do not force mass balance by altering values without an explanation. A difference may represent packaging, moisture, coatings, manufacturing losses, fasteners, or omitted components. Investigate it and record the resolution.
BOM import capabilities by software
The tools below solve different parts of the import problem. Sphera focuses on semi-automating model creation through standardized imports; SimaPro CSVmaker converts an inventory matrix; Ecochain populates products and object libraries; and Dawn maintains imported parts within assemblies, variants, versions, suppliers, and LCA studies. These capabilities are described in the vendors’ Sphera BOM Import page, SimaPro CSVmaker page, and Ecochain import guide.
| Software | Documented import capability | Resulting structure or use |
|---|---|---|
| Dawn | Excel/CSV part import | Parts, assemblies, variants, versions, suppliers, and living product plus LCA data management |
| Sphera LCA for Experts | Standardized BOM imports through an add-on | Semi-automated creation of LCA models |
| One Click LCA | Excel source with column, unit, classification, and resource mapping | Structured review file; not a finished LCA or EPD |
| Earthster | CSV and XLSX Generator templates | Creates or updates product LCA models; supports nested structures |
| Ecochain Mobius | CSV, XLS, and XLSX using a predefined structure | Populates products and object libraries |
| SimaPro CSVmaker | Converts an Excel inventory matrix to CSV | Preserves parameters, comments, process links, and links to existing SimaPro data |
| Athena older BOM utility | CSV, tab-delimited text, other delimited text, and Excel | Three-step BOM import; XML listed as unsupported |
Keep the LCA synchronized with product changes
A successful import should not become another static file. When material, quantity, supplier, variant, or subassembly data changes, identify affected assemblies and rerun the relevant studies. Keep prior revisions so results can be traced to the product definition used at the time.
Dawn can centralize product and environmental data across parts, BOMs, variants, versions, LCA studies, suppliers, and files. It runs product LCAs using Ecoinvent-based databases with EN 15804, EF 3.1, and cutoff methods, then presents hotspots, life-cycle stages, and kg CO2e in impact reports through its product carbon footprint workflow.
A product carbon footprint is the carbon result of an LCA study in Dawn, not a separate product object. ISO 14067 PCF work and EN 15804 EPD work may share inventory data, but they are not the same study by default. Dawn can produce EPD-style tables and product documentation; method choices, missing primary data, and verification remain human responsibilities outside the app.
