Documenting LCI datasets¶

To be reusable and understandable by everyone, a Life Cycle Inventory (LCI) must be documented. Documenting a LCI means adding all the information needed to understand what process it describes and how it has been built. This information, called metadata, is not processed by LCA software but is essential to LCA practitioners.

General Metadata¶

The following metadata are supported by ELDAM:

Author¶

Name	Name of the author	Mandatory
Contact mail	Author’s email	Mandatory
Long-term contact	Email of a person related to the project and available on long term (mostly useful for non-permanent authors such as interns).	Recommended

Unit Process¶

Name	Name of the process	Mandatory
Synonym	Synonym of the process	Optional
Allocation type	Type of allocation used (if one)	Mandatory (if concerned)
Step	End-of-life treatment: Energy recycling, Waste water treatment, Landfilling Energy carriers and technologies: Electricity, Heat and steam, Mechanical energy, Crude oil based fuels, Natural gas based fuels, Hard coal based fuels, Lignite based fuels Materials production: Plastics, Metals, Other mineral materials, Wood, Organic chemicals, Inorganic chemical, Water Systems: Packaging, Construction Transport services: Water, Air, Other transport by Rail or Road (from ELCD categories)	Mandatory
Project	Name of the project this process belongs to	Optional
Step in the project		Optional
Reference year or period	Year or period of validity for the dataset	Mandatory
Dataset validity limit	Date until this dataset should be considered as obsolete	Optional
Location of the process	Geographic location of the process	Mandatory
Technology description		Mandatory
Technology scale	Unspecified; Unknown; Laboratory scale; Pilot scale; Industrial scale; Mixed scale	Mandatory
Technology level	New: for a technology assumed to be on some aspects technically superior to modern technology, but not yet the most commonly installed. Modern: for a technology currently used when installing new capacity, when investment is based on purely economic considerations (most competitive technology). Current: for a technology in between modern and old. Old: for a technology that is currently taken out of use, when decommissioning is based on purely economic considerations (least competitive technology). Outdated: for a technology no longer in use. Undefined: Market activities don’t have a technology level.	Recommended
General comment	Free text for general information about the dataset.	Optional

Mass balance¶

Mass of the inputs	Mass of the material inputs	Mandatory
Mass of the outputs	Mass of the material outputs	Mandatory
Mass difference	If not 0, must be explained in comment	Mandatory

Flows¶

Type	Flow type (Input from technosphere, product, …)	Mandatory
Name	Name of the flow as in SimaPro	Mandatory
Library	Database from which the flow comes	Mandatory
Compartment	For elementary flows only	Mandatory (if concerned)
Sub-compartment/ Waste type	Sub-compartment for elementary flows. Waste type for product and waste treatment product flows.	Recommended
Unit		Mandatory
Amount	Amount of the flow in value or Excel formula. Parameters can be used in formulas with their name directly (as in SimaPro).	Mandatory
Formula	Calculated automatically from Amount field	Calculated
Allocation %	Allocation percentage for products. Set to 100% if one product only.	Mandatory (if concerned)
Category	Category of the flow (as in SimaPro). Subcategories can be used with the following format: Category1/Category2/Category3	Recommended
Data source	Source of the data. If it is a publication or a report, the document must be included in the Elda’s folder.	Recommended
Comment	General comment on the flow	Recommended
Uncertainty	Uncertainty type (Lognormal, Normal, Triangle or Uniform)	Optional
SD	Standard deviation (for Lognormal and Normal)	Optional
Min	Minimum value (for Triangle and Uniform)	Optional
Max	Maximum value (for Triangle and Uniform)	Optional
Modification code	See Characterizing datasets Quality	Mandatory (if concerned)
Modification comment	See Characterizing datasets Quality	Mandatory (if concerned)
Relevance code	See Characterizing datasets Quality	Mandatory
Relevance comment	See Characterizing datasets Quality	Mandatory (if concerned)
Confidence code	See Characterizing datasets Quality	Mandatory
Confidence comment	See Characterizing datasets Quality	Mandatory

Input parameters¶

Name	Name of the parameter (as used in formulas)	Mandatory
Value		Mandatory
Comment	General comment on the parameter	Recommended
Uncertainty	Uncertainty type (Lognormal, Normal, Triangle or Uniform)	Optional
SD	Standard deviation (for Lognormal and Normal)	Optional
Min	Minimum value (for Triangle and Uniform)	Optional
Max	Maximum value (for Triangle and Uniform)	Optional
Parameter level	SimaPro parameter level (Process, Project or Database)	Mandatory

Calculated parameters¶

Name	Name of the parameter (as used in formulas)	Mandatory
Value	Value of the parameter in Excel formula. Excel will compute the value and display it.	Mandatory
Formula	Calculated automatically from Value field	Calculated
Comment	General comment on the parameter	Recommended
Parameter level	SimaPro parameter level (Process, Project or Database)	Mandatory

Dataset¶

Review state	Under progress; Major corrections; Minor corrections; Reviewed and valid Automatically calculated from review data (see Reviewing LCI datasets).	Calculated
Dataset version	See Versioning system	Calculated
Version creator	Creator of this version (author or reviewer)	Mandatory
Contact	Contact of the creator of this version	Mandatory
Date of review	Date of edition of this version	Mandatory
Comment	Comment about the reviewing process and/or this specific version	Recommended
Inventory review state	Review state of the inventory itself. This field can be used to force the review state if every data is valid but the inventory itself needs corrections (missing flow for example).	Optional

Characterizing datasets quality¶

All LCIs do not have the same quality level. A LCI may be of poor quality for various reasons:

It is a draft;

It has been done in a limited time;

The data on the process is inexistent.

Any LCI can be reused, regardless of its quality, provided it is well characterized. The poor quality of a LCI may only concern some of its flows. In that case, the practitioner reusing the LCI can improve these flows if he has more knowledge of the subject or more accurate data for example.

To finely characterize the quality of an LCI flows, three attributes have been defined. For each flow, several codified values are possible. Depending on this value, a comment specific to this flow may be necessary.

Flow modification¶

This attribute only concerns inputs from technosphere. It describes whether the flow comes from a database and whether it has been modified or used as is.

Code	Meaning	Additional information to specify
0	The flow comes from a database as is.
1	The flow is a slight adaptation of a process from a database.	What has been modified and why.
2	The flow is a strongly modified version of a process from a database.	What has been modified and why.
3	The flow is a custom flow developed for the project.	Brief description of the newly created process and reason why it was necessary to create it.

Flow relevance¶

This attribute characterizes whether the flow corresponds to the reality it is supposed to describe. It applies to every flow except products.

Code	Meaning	Additional information to specify
A	The flow is adapted to the reality of the described process
B	The flow does not perfectly fit the reality of the described process but is the best available proxy.	The reality that the flow is supposed to describe and why this flow has been chosen as a proxy.

Confidence on numeric value¶

This attribute describes the confidence level of the author about the amount of the flow.

Code	Meaning	Additional information to specify
Y	The numeric value of the amount of the flow is considered trustworthy.	Origin of the numeric value.
Z	The numeric value of the amount of the flow is not completely accurate and contains a significant but unknown amount of uncertainty.	Origin of the numeric value. Why this value is inaccurate and why has it been used anyway.

Data entry on SimaPro¶

Flow quality data can be entered directly under Simpro in the comment field by respecting simple formatting rules:

The first line of the comment contains the quality data codes;
The following lines contains the code and the comment on this metadata;
If the data doesn’t need a comment, the comment lines can be skipped;
A blank line must be inserted between the quality data and the rest of the comment.

Default format:¶

1AY:
1: Comment on modification
A: Comment on relevance
Y: Comment on confidence

Rest of the comment.

The default format is the format in which comment will be created when exporting a process from an Elda back to SimaPro. Still, multiple formats can be used when entering data on SimaPro.

Examples:¶

-1,A,Y:
1: Comment on modification
Y: Comment on confidence

Comment on relevance wasn't needed so the line is skipped.

(1+A+Y)
- 1 Comment on modification
- Y Comment on confidence

This comment
is on

multiple lines.

0AY
Y Only a comment on confidence

Data sources¶

As for any scientific work, LCI data sources must be referenced. The field Data source of each flow must contain a reference to the source of the data used. If it is a web page, the page URL can be enough if the author considers that the website will remain accessible on long term (ex: Wikipedia), otherwise a copy of the webpage must be included in the Elda folder. Any other type of document (article, report, spreadsheet, …) must be included in the folder.

For particularly complex LCI, data sources can be grouped in subfolders for easier access. In that case, the path of the document must be included in the Data source field.

Elda content (simplified):

Type	Name	Amount	Unit	Data source
Product	Bread	820	g
Input from technosphere	Flour	500	g	Ingredients/bread_recipe.pdf
Input from technosphere	Yeast	10	g	Ingredients/bread_recipe.pdf
Input from technosphere	Salt	10	g	Ingredients/bread_recipe.pdf
Input from technosphere	Oven usage	30	min	howtocookmybred.org/cooking_time
Input from technosphere	Tap water	285	ml	Ingredients/bread_water_content.xlsx
Input from technosphere	Electricity	1.75	kWh	Equipements/oven_manual.pdf
Output/ Emission	Water	15	g	Ingredients/bread_water_content.xlsx

Folder organization:

Bread/	Ingredients/	bread_recipe.pdf
	Ingredients/	bread_water_content.xlsx
	Equipments/	oven_manual.pdf
	bread.xlsm

Using parameters¶

As in SimaPro, Elda files can use parameters for formula calculations. These parameters can be defined by a value (input parameters) or by a formula (calculated parameters). A parameter can be defined at three levels: process, project and database. Project and database parameters can be used by other processes of the same SimaPro project or database.

For calculated parameters, write the formula preceded by = in the Value field. The calculated value will appear in the Value field and the formula will appear in the Formula field. It is possible to use parameters in the formula by using their names directly.

For display reasons, parameters are grouped in blocks. If a block is full, a new block will appear on its right allowing the user to enter more parameters.