The SCIDS project is an industry collaborative project investigating the support of designers with computer technology. It attempts to address the current failings of design support systems which focus on highly dedicated and prescriptive techniques in deference to actual working practices. In addition it considers designers of safety critical systems (aerospace) and mechanisms for additional, specialist support. The prototype produced consists of a design history store with agency provided by software agents to give the specialist assistance. The Designer's Assistant is one such agent, and used in conjunction with the design history a safety case can be addressed and justified. The findings support the growing consensus that memory prosthesis at personal and organisational level may be beneficial to such skilled work.