From 1976 to 1979, Harrison was the London-based commercial manager of the
New Zealand Meat Producers Board. From 1980 to 1983, he was the board's Assistant General Manager based in
Wellington. From 1984, he was Managing Director of the Asian New Zealand Meat Company Limited, known under its trading name
ANZCO Foods. In 1989, Japanese company
Itoham Foods and ANZCO formed a 50–50 partnership and founded Five Star Beef, a company that operates a
feedlot in
Wakanui near
Ashburton; this is New Zealand's largest feedlot and mainly exports to Japan. In 1995, the ANZCO management team led a buy-out of the company from the Meat Producers Board, with Itoham Foods taking a 48.3% minority shareholding and another Japanese company,
Nissui (Nippon Suisan Kaisha Ltd), taking a smaller shareholding. Through that buy-out, the initial investment of NZ$350,000 returned over NZ$40m to the original owners. In 2015, founder Harrison announced that he intended to retire in the near future. In the accompanying restructure in shareholding, Harrison sold down from just over 20% to 14%. In late 2017, Itoham Foods received
Overseas Investment Office (OIO) approval to become to sole owner by obtaining the remaining 35% shareholding. Harrison retired from the company after the March 2018 annual general meeting; he had been at the helm of the company for 34 years, with his initial position of managing director followed as chairperson from 2004. ==Family and private life==