This is the widely used fundamental definition of sustainability as outlined by the Brundtland commission in 1987 (reference: see below).
Beside the technical feasibility, sustainable development has to consider environment, economy and social aspects. A holistic approach is required to develop sustainable processes, resulting in an multiple criteria optimization.
“Our Common Future”; United Nations, World Commission on Environment and Development, Oslo, Norway, 1987; http://www.un-documents.net/wced-ocf.htm; http://www.un-documents.net/our-common-future.pdf (page 41).