The value of establishing design requirements is well-argued and the need for their clear representation in the material used to brief designers is recognised. However, very little attention has been given as to how the design requirements should be represented for use by industrial designers and whether, or how, such representations benefit design. The research presented in the thesis aims to explore approaches to the organisation and presentation of design brief requirements for effective use by designers. We first examined how design requirements are specified, organised and represented in theory and practice. The role of design requirements in the design problem-solving process was analysed to gain insight into how explicit requirement representation might benefit the design process. An experimental study, using protocol analysis, was then conducted to investigate the impact of explicitly representing design requirements in achieving the theoretical benefits for such representations. The results indicate the explicit representation of design brief requirements yields systematic enhancements including increased utilisation of design requirements and the production of solutions assessed as meeting design requirements more successfully. Thus, the findings support the proposition that the manner in which design requirements are represented will impact upon the design process and the designers' performance. In line with the research findings, recommendations are made about how the organisation and presentation of requirements may be manipulated to achieve maximum positive enhancement and minimal negative reduction in the quality of the design process