Life-cycle analysis (LCA) is an effort to assess the environmental impacts of a product or service from its very beginnings to its very end. It is a powerful tool for analysing aspects of systems that can be measured and compared according to a common standard. The aim is to enable a total, whole system overview.

LCA has significant strengths and can contribute much to environmental management and the achievement of sustainability, as evidenced by the achievements of Hewlett Packard and Kyocera (here) via work on remanufacturing and design for disassembly. It has weaknesses that need to be kept in mind too. To get a total view of a system one needs to account for every factor and all interactions – but there us much that cannot be reduced to a number and inserted into a model. Additionally a single, common unit for all varying impact types cannot be established. Social implications of products are generally lacking in LCAs in part because of measurement issues.

Rigid system boundaries make accounting for changes in systems difficult. Accuracy and availability of data can also contribute to misleading conclusions (data from generic processes may be based on averages, unrepresentative sampling, or outdated results). Comparative LCA is criticised because of these considerations.

LCA can provide a lot of room for the researcher to decide what is important, how the product is typically manufactured, and how it is typically used. There has been a lack of consistency in the methods and assumptions used to track carbon during a product life cycle for instance. The wider the variety of methods and assumptions used the more different and potentially contrary conclusions can be.

Many of these weaknesses can be and are being minimised however. Best practice life cycle interpretation is performed with great care, determines the level of confidence in the final results and communicates them in a fair, complete, and accurate way. There are guidelines/standards to help reduce conflicts in results, such as ISO 14040:2006 on basic principles and ISO 14044 on compliance with standards.

Third-party certification plays a major role in today's industry. Independent certification can show a company's dedication to higher quality products to customers and NGOs.

Comparative LCA is now more often used to determine a better process or product to use. LCA is increasingly used to support business strategy, inform research and development, input to product or process design, support and inform education and inform labelling or product declarations.

All over the globe major corporations are either conducting LCA in house or getting others to do it for them - and governments are facilitating the development of national databases to support LCA. When it comes to environmental impact assessment, integrated waste management and pollution studies LCA is now playing a major role.