Although relatively recent in information systems design, the prototyping technique has a long tradition in developing engineering systems. An engineering system is defined as any artificial system that performs actions to achieve a desired transformation of objects undergoing a change of state. We will review the application of and experience with prototyping in engineering systems design and relate these to the development of information systems. Drawing on the strong similarities between the design processes of engineering systems and information systems results in the identification of a number of different types of prototypes that can be used for a variety of purposes and integrated into the various stages of the systems development life cycle. The experience gained from applying the prototyping method in the design of engineering systems permits us to exploit its advantages and to avoid its misapplications when it is used in information systems development.