An article by Ray and Ray published in the IEEE TRANSACTIONS ON ENGINEERING MANAGEMENT (IEEE-TEM) in 2010 raised the issue of resource constraints in innovation and how these constraints shape innovation processes and the innovation design. Their article describes the development of an indigenous digital telephone switching system in India, which was developed at a fraction of the research and development (R&D) costs that comparable systems from developed countries required. Around the same time, the terms frugal innovation and frugal engineering were coined for these kinds of resource-constrained innovations.