A Life Cycle Assessment is an integral part of a systems approach. In the simplest terms, it assesses the impact of a particular product, service or activity over its entire life cycle. For example, if we are studying the overall life cycle impact of a metal, we would have to consider the impacts (i) while it is being mined (in which ever part of the planet), (ii) during transportation (as ore or after processing), (iii) during the processing, (iv) through the conversion of the metal into usable products, (v) through its use as a part of the usable product (or as a component), (vi) through any process of recycling and (vii) through its ultimate disposal (in a landfill).

LCAs are now routinely carried out in many parts of the world for a range of products and services. It is also useful when choosing between strategies to minimize the impact of particular products or services.