The UK continues to be among the leading countries in terms of scientific innovation, but its failure to exploit successfully the results of good research has often been cited in the past decades. Professional engineers must play a role throughout all phases of new product introduction, including particularly the marketing task which has, hitherto, been inadequately recognised. The management of the total task of new product introduction from market study through product concept, design, development and production also needs closer attention from the professional engineer whose ‘formation’ should include the relevant elements. All innovations bring attendant risks of possible delays and excess costs during the development phase. Successful and profitable introduction of new products demands a compromise between market need and scientific creativity, requiring, at all stages, decisions to be made by engineers skilled in risk management. Evolution rather than revolution should be the order of the day. As a demonstration of the principles, the introduction of a new medical linear accelerator for cancer therapy is described. A Linac is a complex machine embracing many engineering disciplines, but which receives scant attention in the engineering literature. It is required to deliver controlled doses of high-energy photons or electrons in the range 4–20 MeV. Some elements of the introduction of the new MEL/Philips SL25 are described, with particular reference to the innovations, such as the beam bending magnet and overall control system. The relevance of the principles for successful product innovation to this practical case are examined.