User-centred design of man-machine interfaces

Users frequently find man-machine interfaces unnecessarily difficult to understand, hard to learn, and badly matched to the needs of their normal work. They find the systems difficult to adapt as their requirements evolve. An instrument with a difficult to use interface leading to user frustration and errors may be a major financial liability for the user organisation. The paper discusses design for usability and considers the European MUSiC project (Measuring Usability of Systems in Context).