Upon leaving academia Norman commenced employment in 1976 with The Plessey Company, a British-based international electronics, defence and telecommunications company, where he was involved with strategic planning. In 1978 he moved to McKinsey & Company, a global management consulting and from where, in 1986, he was seconded to work, until 1987, for the Conservative government of the United Kingdom. Back at McKinsey's, Blackwell was made a partner in 1984 and he remained with the firm until 1995, when a second spell working for a British Conservative Government commenced. That administration's defeat in the 1997 general election saw him again take up private sector employment with National Westminster Bank as director of group development between 1997 and 2000. The new millennium witnessed a change in employment opportunities and he began a new phase in his career as a non-executive director and advisor appointed to a number of public listed companies.