Although developing systems with reusable software components offers considerable scope to speed the delivery of a system, their use also requires us to revise our ideas about the design process. We report on a series of laboratory-based studies in which we observed the processes by which simple component-based designs were developed, paying particular attention to when the documentation for particular components was accessed and what information was being sought at each stage in the development of the solution. We observed quite extensive access to documentation, both for the components that were eventually used and also for those that were discarded during the process.