Mr. Koorevaar has, since 1966, acted as an advisor, interim manager and change agent for a wide range of profit and non-profit organisations in the fields of organisation, control, information and automation. Koorevaar has worked extensively on organisation development programmes and implementation of process- and information management.
In addition, after his resignation as a director at PricewaterhouseCoopers Management Consultants in 1997, he has his own consulting firm specialised in Organization & Management and Business Innovation and IT.