Functional representation: A brief historical perspective

I review research in the last decade in the framework called Functional Representation (FR). FR is a language for describing the function of a device, its structure, and the causal processes in the device that culminate in the achievement of the function. The causal transitions are annotated in specific ways that explain the role of the functions of the components and domain laws in the achievement of various states and hence the function of the device. I describe the uses of FR for simulation, diagnosis and design, among other tasks.