Life Cycle Analyse - Engineering for Society

Sustainability

a process of change in which the use of resources, the direction of investments, the orientation of technological development and institutional change must all be in harmony with each other and increase all present and future possibilities to meet human needs and desires

PPP

People, planet, profit

relevance of the concept of sustainability

to understand the problems the world is facing and to provide direction to developments and actions to solve these issues.

Practical value of using tools to conduct assessments in sustainability

as the tools provide prestructured models, guide data collection, and might even provide databases for data – all of which make it easier to assess

methodological value of using tools to conduct assessments in sustainability

to ensure consistent and transparent assessment providing comparable results

social value of using tools to conduct assessments in sustainability

making problems and solutions understandable and thereby contributing to change or decision making

Material Flow Analysis (MFA)

the systematic assessment of the flows and stocks of materials within a system defined in space and time.

In order to do a good MFA you need

A good definition of goal, scope and system boundaries; At different levels different characteristics and dynamics can be found of which we should be appreciative; A good understanding of dynamics requires understanding the interactions between different levels

The goal of a study defines

what you want to achieve or what you want to know.

System boundaries define

what should be included and excluded in the study.

Life Cycle Assessment

a framework for assessing the environmental impact of products to facilitate decision-making.

the functional unit

a specification of the subject to be studied

The data quality requirement of LCI: technological representativeness

the degree to which the data set reflects specific technology or an average technology mix

The data quality requirement of LCI: time-related representativeness

age of data and the minimum length of time over which data should be collected

The data quality requirement of LCI: geographical representativeness

geographical area from which data for unit processes should be collected to satisfy the goal of the study

The data quality requirement of LCI: precision

a measure of the variability of the data values (e.g., variance)

The data quality requirement of LCI: completeness

percentage of flows that are measured or estimated

The data quality requirement of LCI: representativeness

a qualitative assessment of the degree to which the data set reflects the actual population of interest (i.e., geographical coverage, period and technology coverage)

The data quality requirement of LCI: consistency

qualitative assessment of whether the study methodology is applied uniformly to the various components of the analysis

The data quality requirement of LCI: reproducibility

a qualitative assessment of the extent to which information about the methodology and data values would allow an independent practitioner to reproduce the results reported in the study

Life Cycle Inventory Analysis (LCI)

The phase in which material and energy flows of the product system are quantified.

classification

sorting the inventory parameters according to the type of environmental impact they contribute to.

characterization

the contributions of the emissions and resource consumptions to each environmental impact are calculated.

normalization

converting characterized scores to relative impacts to make the results more understandable

making sense of the assessment: the completeness check

If information is missing or incomplete, this should be reported, justified, and checked whether this potentially influences the validity of the assessments.

making sense of the assessment: the consistency check

is performed to investigate whether the assumptions, methods, and data have been applied consistently throughout the LCI/LCA study

making sense of the assessment: the reliability and sensitivity check

is used for uncertain and critical data and assumptions. This should show whether the results are trustworthy and consistent and whether the assessment results are accurate

making sense of the assessment: the identification of significant issues and coming to interpretation

requires careful and critical interpretation of the findings of inventory, characterization, normalization, and weighing, often represented in diagrams

making sense of the assessment: conclusions and report limitations and recommendations for the intended audience in line with the defined goal and the intended application

This requires integrating the outcomes of the other elements of the interpretation phase, and drawing on the main findings from the earlier stages of the LCA

Responsible Research and Innovation (RRI)

involves societal stakeholders in early technological development and assessment phases.

Sustainable Development

Development/process of change where resources, investments, technological development and institutions support present and future human needs.

Goal Definition

Defining what the study wants to achieve or find out.

Scope Definition

Defining what is included in the study and how broad or detailed it is.

System Boundary

The line that determines what is included and excluded in the study.

Life Cycle Impact Assessment (LCIA)

The phase in which inventory flows are translated into environmental impact categories.

Impact Category

A type of environmental impact to which emissions or resource use can contribute.

Weighting / Weighing

Assigning relative importance to different environmental impact categories.

Interpretation Phase

The phase where results are checked, significant issues are identified, and conclusions, limitations and recommendations are formulated.

Significant Issues

The most important findings or contributors in an LCA that strongly influence the results.

Sensitivity Check

Checking how much uncertain or critical assumptions influence the final results.

Sustainable Development Goals (SDGs)

17 UN goals that give more concrete direction to sustainability by combining social, environmental and economic goals.

Assessment

Judging or deciding the amount, value, quality or importance of something.

Assessment tools

Pre-structured ways to assess sustainability problems, solutions or progress.

Material basis of sustainability

The idea that material and energy flows connect the economy to environmental impact.

Used materials

Extracted resources that enter the economy for processing or consumption.

Unused extraction / hidden flows

Materials that are extracted or displaced but do not enter the economic system.

Direct flows

The actual weight of products and the materials they are made of.

Indirect flows

Materials required for production, transport, use and waste phases outside the visible product.

Concentrated use

Material use in products, infrastructure or solid waste that can be contained.

Dissipative flows

Materials dispersed into the environment during use.

Elephants

Large-volume material flows that cause problems because of their size.

Scorpions

Low-volume material flows with high environmental impact or toxicity.

Industrial Ecology

The study of material and energy flows through industrial systems and their environmental impact.

Substance Flow Analysis (SFA)

Analysis of flows and stocks of a specific substance.

Energy Flow Analysis (EFA)

Analysis of energy flows through a system.

Material and Energy Flow Analysis (MEFA)

Combined analysis of material and energy flows.

Mass conservation

The principle that matter is not lost: inputs equal outputs plus accumulation.

Balance equation

Incoming flows = outgoing flows + accumulation.

Source

A stock outside the system boundary from which an inflow originates.

Sink

A stock outside the system boundary to which an outflow goes.

Process

A step in a system where material is transformed, stored or distributed.

Performance indicator

A measurable indicator used to evaluate system performance, such as useful output / total input.

Indicator element

A selected element used to characterize a system, such as carbon for climate impact.

Spatial scope

The geographical scale included in the study.

Temporal scope

The time period included in the study.

Functional scope

The function or purpose included in the study.

Cradle-to-grave

A full life-cycle boundary from raw material extraction to end-of-life.

Cradle-to-gate

A partial life-cycle boundary from raw material extraction to factory gate.

Gate-to-gate

A system boundary limited to one factory or production stage.

Cradle-to-cradle

A life-cycle approach where end-of-life becomes reuse, upgrade or recycling.

Cut-off criteria

Rules for excluding small or irrelevant flows or processes from a model.

Allocation rules

Rules for assigning impacts or costs to different products from the same process.

Pedigree matrix

A tool to keep track of data quality across dimensions such as reliability, completeness and representativeness.

Research log

Notes documenting research steps, sources, findings and remaining issues.

20-80 rule

The idea that 20% of the effort can often achieve 80% of the result.

Flow chart

A diagram using boxes and arrows to show processes and material flows.

Sankey diagram

A diagram where arrow width is proportional to the size of material flows.

Life Cycle Thinking (LCT)

A holistic perspective that considers burdens and benefits from raw material extraction to end-of-life.

Product system

The network of processes, components, materials and flows that make up a product’s life cycle.

Reference flow

The amount of product or service needed to fulfill the functional unit.

Comparative LCA

An LCA that compares alternative products, technologies, scenarios or configurations.

Screening LCA

A quick-scan LCA that identifies major impacts or hotspots using available or average data.

Full LCA

A detailed LCA with thorough data, uncertainty reflection and often software support.

Broadening and deepening LCA

Combining LCA with other approaches such as social LCA, life cycle costing, circularity or criticality indicators.

Foreground system

The product-specific part of an LCA model requiring primary data.

Background system

The part of an LCA model representing the wider industrial economy, often using secondary database data.

Primary data

Specific data collected from the product, producer, developer or operator.

Secondary data

General or average data from databases, literature or experts.

Bill of Materials

A list of product components, materials and their quantities.

Structural tree diagram

A diagram showing product, components, subcomponents and materials in relation to the functional unit.

Impact category

A type of environmental impact, such as climate change, acidification or eutrophication.

Midpoint impact

An impact calculated per environmental problem, such as global warming potential.

Endpoint impact

A further translated impact related to areas of protection such as human health or ecosystem quality.

Areas of protection

Broad endpoint areas such as human health, ecosystem quality and resource availability.

Characterization factor

A factor expressing the relative environmental impact per kilogram of substance.

CO2-equivalent

A unit expressing climate impact relative to CO2.

Global Warming Potential (GWP)

The extent to which a substance contributes to radiative forcing compared to CO2.

Weighted score

A single aggregated score after assigning importance to different impact categories.

Distance to policy target

A weighting method based on how far an impact is from policy goals.

Distance to scientific target

A weighting method based on how far an impact is from scientific limits.