Methods and Tools

The Center for Sustainable Systems is a leader in Industrial Ecology research and education, specializing in life cycle assessment of human built systems that rely on natural resources to provide for society's needs. The Center has completed more than 100 research projects using a variety of methods and tools, including life cycle assessment, life cycle design, life cycle costing and life cycle optimization.

Industrial Ecology

Industrial Ecology seeks to understand the interactions between industrial systems, ecological systems, and societal needs. Material and energy flows driven by human production and consumption are traced throughout the economy and their ecological consequences characterized. A more sustainable relationship between industrial and ecological systems is guided by conservation of non-renewable resources, pollution prevention, and inter-generational and inter-societal equity.

Natural ecosystems are highly integrated webs of producers (who convert sunlight into food energy), consumers (including herbivores and carnivores) and decomposers (bacteria and fungi) that convert waste into nutrients. Natural ecosystems can serve as a model for industrial systems to better utilize renewable energy sources and eliminate waste through remanufacturing, reuse and recycling.

Community Metabolism Modeling

Communities across the US face enormous challenges regarding urbanization, resource distribution, land conversion, population growth, and the extension of infrastructure. Community metabolism modeling draws on the disciplines of biology, engineering, and physics to increase efficiency and reduce environmental impact of material and energy flow through human communities. CSS has performed several analyses of the local Ann Arbor and University of Michigan communities.

Life Cycle Design

Life Cycle Design is a framework for integrating environmental considerations into product development by considering all stages of a product's life cycle, from raw material acquisition through manufacturing and use, to final disposal of wastes. Activities include identifying system requirements, selecting strategies for meeting these requirements, and evaluating tradeoffs among system alternatives. Successful environmental integration often must be achieved within the context of shortening time to market cycles, more stringent regulations, and global competitiveness. The objective of life cycle design is to enhance environmental performance across the life cycle while also optimizing functional performance, cost, and regulatory/policy requirements that influence the product system.

Demonstration projects with industrial partners have targeted a wide range of products. Automotive products investigated includes oil filters (AlliedSignal), air intake manifolds (Ford), transmission parts (Ford), fuel tanks (GM), automotive film (3M), instrument panels (Chrysler, Ford, GM, and U.S. EPA Common Sense Initiative). Electronic products include business telephones (AT&T), flat panel displays (Optical Imaging Systems), photovoltaics (United Solar Systems Corporation); other systems studied include milk and juice packaging (Dow), residential homes, and water-based technologies for garment cleaning. Design analysis of these product systems highlights opportunities for improvement.

Life Cycle Assessment

Life Cycle Assessment, as defined by the Environmental Protection Agency, is an analytical tool to evaluate the environmental consequences of a product or activity holistically, across its entire life. CSS has adopted the International Organization of Standards (ISO) Life Cycle Assessment guidelines as defined in 14040 series documents.

Typically there are three phases in a Life Cycle Assessment.

  1. inventory analysis - identification and quantification of energy and resource use and environmental releases to air, water, and land.
  2. impact analysis - technical qualitative and quantitative characterization and assessment of the consequences on the environment
  3. improvement analysis - evaluation and implementation of opportunities to reduce environmental burden.

CSS has conducted assessments on product systems of varying complexity from milk and juice packaging to automotive transmission parts to larger more complex systems such as total vehicle and residential homes.

For more information about Life Cycle Assessment visit the EPA resource page on the topic.

Life Cycle Costing (LCC)

Life Cycle Costing(LCC) is a tool for evaluating all monetary costs associated with a system from acquisition, operation, maintenance, service and retirement. LCC addresses liabilities and hidden and less-tangible costs as well as externalities not accounted for in the current market system.

Dynamic Life Cycle Assessment

Dynamic Life Cycle Assessment accounts for changes in products or activities over time as well as the evolution of background systems that these product or activities depend upon (e.g. raw material supply chains and energy infrastructure). Many Life Cycle Assessments provide only a “snapshot” of the environmental consequences of products at one point in time by using static parameters. However, Dynamic Life Cycle Inventories can account for how new technologies and the expansion of renewable energy systems alter the environmental impacts from past, present, and future product usage.

Life Cycle Optimization

Dynamic Life Cycle Assessment accounts for changes in products or activities over time as well as the evolution of background systems that these product or activities depend upon (e.g. raw material supply chains and energy infrastructure). Many Life Cycle Assessments provide only a “snapshot” of the environmental consequences of products at one point in time by using static parameters. However, Dynamic Life Cycle Inventories can account for how new technologies and the expansion of renewable energy systems alter the environmental impacts from past, present, and future product usage.

Carbon Footprint

A carbon footprint refers to the overall amount of greenhouse gas emissions associated with the consumption of an individual good or service or the sum of all goods and services consumed by an individual, a group, or an economy. In order to represent all greenhouse gas emissions as a single value, they are expressed in terms of the amount of carbon dioxide emissions that would cause an equivalent level of global warming.

Risk Analysis

Risk Analysis is an area of study that seeks to understand the environmental, health, and economic threats from the occurrence of undesirable events such as the failure of man-made systems or the occurrence of abnormalities in natural cycles (natural disasters, droughts, etc.). Identifying potential threats and failure modes, quantifying the probability of loss, and estimating the magnitude potential damages are necessary to understand and manage risks.