In 1974, the LAS commissioned a computer-aided despatch system that remained unused for 13years because union members refused to operate it. A replacement system failed acceptance tests in 1990 and a further replacement system was designed and ordered. On 26 October 1992, the LAS started to use the new computer-assisted dispatch (CAD) system, known as LASCAD. Poorly designed and implemented, its introduction led to significant delays in the assigning of ambulances, with anecdotal reports of 11-hour waits. A subsequent enquiry found no evidence to support union claims that up to 30 people may have died as a result of the crash. The crash coincided with hundreds of control room exceptions messages related to alerts that crews responding to emergencies had not reported mobile, and the ambulance had not moved within 3minutes of despatch. The then-chief executive, John Wilby, resigned shortly afterwards. This failure is often cited in case studies of poor engineering management.