Few would disagree with the assertion that safe engineering starts from the early stages of system design and should be maintained throughout the lifecycle. Different engineering domains have developed, mostly informal, frameworks with which they hope to promote this attitude. An interesting question for the KBS community is whether some of our methods for knowledge representation and reasoning can be used to assist in understanding, representing and interpreting such frameworks. This paper concentrates on what is (arguably) the area of greatest concern: relating system requirements to high level design. We highlight what appear to be the major difficulties which face us in this area, using examples from systems which have been built to tackle them.