Product Life Cycle
Product Life Cycle: is defined as consecutive and interlinked stages of a product system, from raw material acquisition or generation of natural resources to the final disposal [according to ISO 14040]. NOTE that "Product" includes any goods or service.
Schematic diagram illustrates the concept of “Life Cycle of a product”
Life Cycle Assessment (LCA)
A 'Life Cycle Assessment' ('LCA', also known as 'life cycle analysis', 'ecobalance', and 'cradle-to-grave analysis') is the investigation and evaluation of the environmental impacts of a given product or service caused or necessitated by its existence.
Goals and purpose of LCA
The goal of LCA is to compare the full range of environmental and social damages assignable to products and services, to be able to choose the least burdensome one. At present it is a way to account for the effects of the cascade of technologies responsible for goods and services. It is limited to that, though, because the similar cascade of impacts from the commerce responsible for goods and services is unaccountable because what people do with money is unrecorded. As a consequence LCA succeeds in accurately measuring the impacts of the technology used for delivering products, but not the whole impact of making the economic choice of using it.
The term 'life cycle' refers to the notion that a fair, holistic assessment requires the assessment of raw material production, manufacture, distribution, use and disposal including all intervening transportation steps necessary or caused by the product's existence. The sum of all those steps - or phases - is the life cycle of the product. The concept also can be used to optimize the environmental performance of a single product (ecodesign) or to optimize the environmental performance of a company.
Common categories of assessed damages are global warming (greenhouse gases), acidification, smog, ozone layer depletion, eutrophication, eco-toxicological and human-toxicological pollutants, habitat destruction, desertification, land use as well as depletion of minerals and fossil fuels.
The procedures of life cycle assessment (LCA) are part of the ISO 14000 environmental management standards: in ISO 14040:2006 and 14044:2006. (ISO 14044 replaced earlier versions of ISO 14041 to ISO 14043.)
Four main phases of LCA
Illustration of LCA phases. These are often interdependent in that the results of one phase will inform how other phases are completed.
According to the ISO 14040[1] and 14044[2] standards, a Life Cycle Assessment is carried out in four distinct phases as explained underneath.
First Stage: Goal and scope
In the first phase, the LCA-practitioner formulates and specifies the goal and scope of study in relation to the intended application. The object of study is described in terms of a so-called functional unit. Apart from describing the functional unit, the goal and scope should address the overall approach used to establish the system boundaries. The system boundary determines which unit processes are included in the LCA and must reflect the goal of the study. In recent years, two additional approaches to system delimitation have emerged. These are often referred to as ‘consequential’ modeling and ‘attributional’ modeling. Finally the goal and scope phase includes a description of the method applied for assessing potential environmental impacts and which impact categories that are included.
Second Stage: Life cycle inventory
This second phase 'Inventory' involves data collection and modeling of the product system, as well as description and verification of data. This encompasses all data related to environmental (e.g., CO2) and technical (e.g., intermediate chemicals) quantities for all relevant unit processes within the study boundaries that compose the product system. Examples of inputs and outputs quantities include inputs of materials, energy, chemicals and 'other' - and outputs of air emissions, water emissions or solid waste. Other types of exchanges or interventions such as radiation or land use can also be included.
Usually Life Cycle Assessments inventories and modeling are carried out using dedicated software packages. Depending on the software package used it is possible to model life cycle costing and life cycle social impacts in parallel with environmental life cycle.
The data must be related to the functional unit defined in the goal and scope definition. Data can be presented in tables and some interpretations can be made already at this stage. The results of the inventory is an LCI which provides information about all inputs and outputs in the form of elementary flow to and from the environment from all the unit processes involved in the study.
Third Stage: Life cycle impact assessment
The third phase 'Life Cycle Impact Assessment' is aimed at evaluating the contribution to impact categories such as global warming, acidification, etc. The first step is termed characterization. Here, impact potentials are calculated based on the LCI results. The next steps are normalization and weighting, but these are both voluntary according the ISO standard. Normalization provides a basis for comparing different types of environmental impact categories (all impacts get the same unit). Weighting implies assigning a weighting factor to each impact category depending on the relative importance. The weighting step is not always necessary to create a so called “single indicator”. See for instance the prevention based model of the Eco-costs.
Fourth Stage: Interpretation
The phase stage 'interpretation' is an analysis of the major contributions, sensitivity analysis and uncertainty analysis. This stage leads to the conclusion whether the ambitions from the goal and scope can be met. More importantly: what can be learned from the LCA? All conclusions are drafted during this phase. Sometimes an independent critical review is necessary, especially when comparisons are made that are used in the public domain.
References:
- ISO 14000 series.
- Wikipedia® (a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization).
Eng.AHMED ZAHER
(Certified Trainer Safety of NASP- USA (STS&SPS
Member of the Arab Society for Occupational Safety and Health and theEnvironment
Mobile: 01003987189 & 01002151163
