According to Houkes and Vermaas’s use plan approach, engineering design is fundamentally about constructing and communicating use plans: plans to achieve certain goals that involve the use of one or more objects. This chapter details how such use plans should be designed, communicated and executed. It goes into the relation between plan design and artefact design and explains why Houkes and Vermaas consider a plan-based account of design more fundamental and more accurate than traditional function-based designs.
The use plan approach not only offers an abstract conceptualisation of the design process, but also provides standards based on practical rationality to evaluate use plans with, particularly effectiveness and efficiency. In order to give an overview of the strong and weak points of the approach, it will be compared with function-based and affordance-based accounts of design. Finally, some criticisms will be discussed, namely regarding the ability of the use plan approach to deal with artefact components; with situated rather than with plan-based actions and with potential biases in its method of abstraction from actual design processes.