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Metadata Guidance

This document provides detailed information on metadata fields for data on the FLCAC. Each field in this document corresponds to a field in openLCA.

As FLCAC interagency coordination increases, the new standard for data formats and documentation is being advanced. To move toward interoperability and transparency, FLCAC harmonization of digital data access and preservation will increase collaboration potential and the reviewability of the LCA data exchange process. These efforts will significantly reduce not only data acquisition costs but also computer- and human-based misinterpretation errors, and thus, data misuse. As such, and to be more aligned with international protocols for all newly developed data, the current FLCAC standard is to strive for 100% metadata completion.

The sections in this document correspond to the tabs[1] and sections within the openLCA software.


General Information

Key process level metadata are compiled on the General Information tab.

alt text Image of ‘General Information’ process tab within openLCA

Name (Mandatory)

The naming conventions are as follows:

Base name[2]; treatment received[2], production route(s)[2], standard(s) fulfilled[3]; production or consumption type[3], location type[3]; quantitative flow properties

For consistent nomenclature, use the following guidelines:

Example(s) With 3 components:

With 2 components:

Category (Automatic)

The category/subcategories schema follows North American Industry Classification System (NAICS). See Categorization of the Data Submission Handbook for instructions on how to categorize flows and processes.

This field is automatically populated based on the folder that your process is located in.

Example(s)

Description (Mandatory)

A legible overview of the process description, i.e., technical scope, functional unit, system boundaries, and any other information needed for unambiguous data interpretation and application.

Functional Unit: The reference unit of your life cycle inventory that allows quantification of the defined function. It provides a reference to which the inputs and outputs can be related.

Technical Scope: Cradle-to-gate, cradle-to-grave, gate-to-gate, gate-to-grave.

System boundaries: Overview of included and excluded processes, i.e., boundaries between the technosphere and nature; geographic and temporal scope; boundaries between this and other technosphere systems. Be brief, detailed information on system boundaries can be provided in the Sampling procedure field.

Other Relevant Information: Include relevant modeling information regarding the inclusion of avoided products, co-products, cut-off flows, proxies, etc.

Example(s)

Version (Automatic)

Per ILCD, the data set version is formatted as follows: the first two digits indicate major updates, the second two digits refer to minor revisions and error corrections; the final three digits are used for automatic and internal version counting during dataset development.

Unless discussed in advance with the Data Curator, the value will be generated automatically by openLCA.

Example(s)

01.00.000

Last change (Automatic)

The date and time when the dataset was last saved.

Example(s)

2018-04-01T17:38:55-0600

UUID (Automatic)

32-digit Universally Unique Identifier (UUID) for the dataset. Every element in an openLCA database has a UUID. UUIDs cannot be set, they are assigned by openLCA.

Example(s)

961fad56-bde2-4fbe-8895-5be03461729b

Infrastructure (Mandatory)

Checking the box indicates that the process accounts for infrastructure requirements in its inventory. Leave this box unchecked if infrastructure requirements are not included in the process. More information on the inlcusion of infrastructure should be described in the System Boundaries.

Example(s)

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Time (Mandatory)

Start Date

Start date for the time period that the process data represents. The date format is MM/DD/YYYY.

Example(s)

01/01/2017

End Date

End date for the time period that the process data represents. The date format is MM/DD/YYYY.

Example(s)

12/31/2017

Description

Provide information regarding the temporal characteristics and period that the process data represents. Information can also be provided pertaining to secondary data source time periods.

Examples can include explanation of the valid time period, any temporal aggregation (e.g., averaging multiple years of primary data), data collection period, and seasonal/annual variations.

Example(s)

Geography (Mandatory)

Location

The geographic area to which the unit process data were collected or refer. If multiple locations were used, indicate the location using the lowest common geographic resolution (e.g., if data for several states across the US were collected then enter ‘US’). Describe the locations in the geography ‘Description’ field.

Example(s)

Description

Description of the process’ geographic representativeness and any geographic aggregation methods as well as name(s) and production volume(s) or capacity of specific included site(s), where applicable.

Example(s)

Technology (Mandatory)

A short (i.e., 1-3 paragraphs), general description of the process intended technical scope, representativeness, and applicability of the process. Include the following information, as applicable:

Example(s)

Data Quality

See Data Quality Guidance for examples and details on assigning data quality.

Process Schema (Mandatory)

Matrix

Use the US EPA - Process Pedigree Matrix, this matrix comes preloaded in many FLCAC repositories. This matrix can also be found in the Commons Core Database which can be imported as a skeleton structure into any openLCA database.

Data Quality Entry

Once you have selected the US EPA - Process Pedigree Matrix, select ‘(not specified)’ next to the ‘Data quality entry’ field and select the appropriate data quality scores for the ‘Process Review’ and ‘Process Completeness’ fields.

Example(s)

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Flow Schema (Optional)

Matrix

Use the US EPA - Flow Pedigree Matrix, this matrix comes preloaded in many FLCAC repositories. This matrix can also be found in the Commons Core Database which can be imported as a skeleton structure into any openLCA database.

Data Quality Entry

Select the US EPA - Flow Pedigree Matrix on the ‘General Information’ tab and enter data quality scores for each exchange in the inventory on the ‘Inputs/Outputs’ tab.

Detail any assumptions used to assign these scores in the Data treatment field.

Example(s)

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Social Schema (Optional)

The FLCAC does not require social schema.


Input/Output

The Inputs/Outputs tab is where the life cycle inventory of the process is defined. It can include data on Elementary Flows, Technosphere Flows, and/or Waste Flows.

alt text Image of ‘Inputs/Outputs’ process tab within openLCA

Flow (Mandatory)

Elementary Flows: Should only be from the FEDEFL.

Example(s) alt text

Technosphere Flows: Flows should be based on the ILCD naming convention. Read about technosphere flow alignment on the FLCAC here.

Example(s) alt text

Quantitative Reference Flow: The quantitative reference flow is the designated output of a process. The quantitative reference flow is bolded and can be in the inputs or outputs section depending on the process type. A process must have a quantitative reference flow to be created.

Example(s) alt text

Category (Automatic)

Category is determined based on the folder that the flow is contained within. The FLCAC uses NAICS Categories to organize flows and processes, read about FLCAC Categorization here.

Example(s) alt text alt text

Amount (Mandatory)

Flow quantity

Example(s) alt text

Unit (Mandatory)

Flow unit; the openLCA software includes a set of unit groups and units. These units must be used to ensure proper data importation.

Example(s) alt text

Costs/Revenues (Optional)

This field is provided for documenting life cycle costing (LCC) data. The currency and costs may be provided for each flow; the costs per unit are automatically generated based on this information and flow amount.

This field is not required and should be left blank if no life cycle costing data is available. Most LCI data on the FLCAC does not include life cycle costing data.

Example(s) alt text

Uncertainty (Optional)

Describe flow’s data uncertainty. The distribution type, mean, and standard deviation may be provided. This information, while not required, is encouraged. Documentation of how the uncertainty is calculated should be added to the process metadata, for example in the Modeling constants. Details on the available uncertainty options can be found in the openLCA manual. Uncertainty data are only used when performing a Monte Carlo analysis.

Example(s) alt text

Inputs: Avoided Waste (Optional)

If there is a scrap or waste flow that is utilized in your process, the flow may be listed as an input to your dataset and marked as an avoided waste.

Outputs: Avoided product (Optional)

Used to indicate allocation has been avoided in a multi-functional process. This box should only be checked for the by-product flow(s). For example, if a process produces steam and offsets natural gas, then natural gas would be entered as an output flow and the avoided product box would be checked.

Example(s) alt text

Provider (Mandatory)

For every non-cutoff technosphere flow, a provider must be selected. A provider connects the flow to an upstream process producing that flow. Every non-cutoff technosphere flow should have at least one provider option.

Example(s) alt text

Data quality entry (Optional)

See the flow data quality section.

This information is not required, but if provided it increases the usefulness of a process.

Location (Optional)

Flow level locations can be provided if the location for a specific flow level exchange differs from the process location.

Example(s) alt text

Description (Optional)

Briefly describe the flow’s relationship to the process and assumptions used to obtain the quantitative reference or data quality.

Types of information to include in the flow description field:

Example(s)

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Documentation

The Documentation tab provides additional process level metadata.

alt text Image of ‘Documentation’ process tab within openLCA

LCI Method

Process type (Mandatory)

Indicate whether the data represent a unit or system process.

Example(s)

LCI method (Mandatory)

Indicate whether the LCI method was attributional, consequential, input/output, hybrid, etc. Can include caveats regarding inclusion of the process in a product system.

Example(s)

Modeling constants (Mandatory)

State the primary assumptions used to create this process. Detail how the process differs from the original source.

Example(s)

This process was adapted from a Smith, 2016 process for wood pellet manufacturing for pellets of a specific energy value in Europe. Process weight factors were adapted for the energy density of a typical US biomass fuel.

Data source information

Data completeness (Mandatory)

This field is comprised of three elements:

  1. Treatment of Missing Environmental Data: List and describe accounting methods for missing environmental data (e.g., cut-off rules) and/or intentional environmental data omissions.

  2. Treatment of Missing Technosphere Data: List and describe accounting methods for missing technosphere data and/or intentional technosphere data omissions.

  3. Mass Balance: Either quantify and describe the mass imbalance ((mass of material outputs - mass of material inputs)/mass of material outputs) or state, “The mass balance for this process was not calculated.”

Example(s)

Elementary flows are cut-off at less than 1% based on environmental relevance. Technosphere flows are cut-off at less than 1% based on environmental relevance. The mass imbalance for this unit process is -17.87 kg (-0.72%).

Data selection (Mandatory)

Detail how data was selected for this process. If data was excluded, explain why.

Example(s)

Data treatment (Mandatory)

This field consists of two sections:

  1. Detailed description of the methods and assumptions used to transform primary and secondary data into flow quantities through recalculating, reformatting, aggregation, or proxy data.
  1. Describe any assumptions that were used when assigning data quality scores.

Example(s)

A horizontally weighted average was calculated from the primary data collected from 4 producers. To indicate known emissions while protecting the confidentiality of individual company responses, some emissions are reported only by the order of magnitude of the average. Flow level data quality scores assume that the reference year is 2024.

Sampling procedure (Mandatory)

This field is comprised of three elements:

  1. System Boundary Conditions: A description of what is included and excluded from the system boundaries.

  2. Data collection: A description of how data were collected for this process.

  3. A description of if and how uncertainty was calculated for this process. If uncertainty was not calculated, this should be explicitly stated.

Example(s)

Data collection period (Optional)

Include any additional information regarding data collection time period that was not covered in the Time field.

Example(s)

All primary data were collected from 2015 to 2016. Secondary data were collected from 2005-2016 (NREL 2016; Wernet et al. 2016).

Use advice (Optional)

Detail information that a data user needs to be aware of when using this process.

This field is highly recommended if use advice is applicable to a process.

Example(s)

Reviews

Review type (Mandatory)

Choose the appropriate review type from the dropdown menu in openLCA. Options: dependent internal review, independent internal review, independent external review, accredited third party review, independent review panel, not reviewed.

Review report (Optional)

If a review report is available, then reference that report in this field using a source object. If there are relevant details regarding the review in another source, cite that source and specify the section where review details can be found in the Review details field.

See the Sources section for details on how to add a source into openLCA.

Review details (Optional)

Note any relevant details regarding the review here, such as which section in the referenced source can the review details be found.

Example(s) alt text

Sources (Mandatory)

Reference to the publication or entity from which data or methodology were obtained. Also include any other sources referenced throughout the metadata. Do not include full citations in other metadata fields, but rather use a shortened citation (Smith, 2024) and include the full citation as an openLCA source.

The field is populated from the list of Source objects in the openLCA navigation tree.

New sources should use “Author (YEAR) Abbreviated Title” format for the Name such that these information display in the openLCA navigation panel.

Example(s) alt text

Administrative Information

Project (Optional)

Information about the project in which the data were generated. Where applicable, this field should indicate the project name, funding institution(s) or organization(s), and the grant or contract names and numbers.

This field is not required if this information is not available.

Example(s) This project was supported by the Biomass Research and Development Initiative, grant no. 2011-10006-30357 from the USDA National Institute of Food and Agriculture.

Intended Application (Mandatory)

This field consists of 5 elements:

  1. Use one of the four Main Goal Situations below to describe how the process is intended to be used. The term, “Main Goal Situations,” refers to an LCA study’s primary intended purpose per the ILCD Handbook’s Detailed Guidance.
  1. Target audience and the context for which the model was built (e.g., carbon footprint, Environmental Product Declaration (EPD), policy development, policy information, generic unit process data, etc.).
  2. Indicate the completeness level of the elementary flows such that users can interpret the correct application of LCIA methods to the dataset. If the data were originally developed and analyzed with a LCIA method, indicate the method utilized here. If categories in that LCIA method should not be evaluated with this dataset also note these.
  3. If these data are an update to a previously published dataset, a note should be included here.
  4. Any additional details regarding the intended application/use of this process.

Example(s)

Situation C1 - Accounting, with system-external interactions - The intended application is a purely descriptive accounting / documentation of the analysed system including existing interactions with other systems in the LCI model.

The target audience of this model includes LCA practitioners, industry, and the general public. A full inventory of environmental flows are included; thus this unit process can be used for a full range of LCIA impact categories. The original study results were analyzed using the TRACI LCIA factors. These data are an update to the previously published dataset from 2010.

These data are intended to be used as an average dataset accepted by the North American plastics/chemical industry.

Data set owner (Mandatory)

Name of the person or entity that owns the dataset directly from which the process was generated. The data set owner is often the data commissioner.

Data generator (Mandatory)

Name of the person or entity responsible for generating the dataset from which the process was generated or for updating of the data.

Data documentor (Mandatory)

Name of the individual or entity responsible for formatting and submitting the data.

These fields are populated from the list of Actors in the openLCA navigation tree.

Example(s)

alt textalt textalt text

Publication (Mandatory)

Reference to an openLCA Source that illustrates how the processes’ LCI data were developed and/or used, i.e., a foundational publication that illustrates how the data are used. The field is populated from the list of Sources in the openLCA navigation tree. Follow the instructions in the Sources section to create a new source.

Example(s)

alt text

Creation date (Automatic)

The date and time when the dataset was created. This field will be automatically generated.

Example(s)

6/1/18 12:45 PM

The openLCA software has a checkbox that will indicate whether the dataset is copyrighted. This box should remain unchecked.

Example(s)

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Access and use restrictions

For USLCI datasets please copy and paste the Data Use Disclaimer Agreement found here into this field.

For other FLCAC repositories, please contact the repository owner for repository specific guidance on this field.


Allocation

This tab allows for customization of allocation for multi product processes. Details on allocation approaches are described in the openLCA manual

alt text Image of ‘Allocation’ process tab within openLCA

Default Method (Mandatory)

For multi-functional processes, choose the process allocation method: causal, economic, or physical allocation methods.

Physical and Economic allocation (Automatic)

The reference flow is listed first by default. The primary product and co-products must have the same flow property.

Physical allocation factors are based on the physical (e.g., mass or energy) ratio of the product flows. Economic allocation factors are based on the economic value of the product flows.

The ratio for the product will be 1.0 for a single-output process. For multi-output processes, the ‘Calculate default values’ button will automatically calculate the ratios based on the default (reference) flow property. Economic flow properties or cost must be included to automatically calculate economic allocation factors.

Causal allocation

Allocation factors can be set by the data provider for individual flows based on a methodology described in the metadata.

Footnotes
  1. Three openLCA process tabs are not included in this guidance ‘Parameters’, ‘Social aspects’, and ‘Direct impacts’. Data providers do not need to provide any information on these tabs. Please discuss the use of parameters with the Data Curator if your data submission includes parameters.

  2. Mandatory field

  3. Mandatory field if relevant to the process. If not, it can be ignored.