Most of the technical work required in the twelve cases was also similar to other projects in their industries. The differences in managing these urgent and unexpected projects were in the concentration of authority and leadership dedicated to the project linking the sponsors, other stakeholders and project teams; the simultaneous involvement of all levels of management in once-only decisions; reliance on oral commitments; making maximum use of all usable resources; and the immediate acceptance of cost uncertainty. These differences are particular to the combination of unexpectedness and urgency. If a project is unexpected but not urgent, it could be defined and budgeted in the normal way before starting it. If it is already expected and defined but becomes urgent, its schedule can be accelerated as exemplified in ‘fast track’ practice. If a project is both unexpected and urgent it might seem obvious that commitments may have to be made orally, all possible resources used and the consequent cost accepted. Less obvious until reported from the case studies was that all interests should be represented at the start in an integrated management structure so as to provide a dedicated system of project stakeholders working with dedicated project leadership.