Allan started his career in Mars Confectionery as a Salesman in 1974. He worked his way up through the company before leaving in 1991.
He then joined Pedigree Petfoods, where he was Sales Director until his appointment in 1992 to Asda Supermarkets. He began his career in Asda as Group Marketing Director and was appointed Chief Executive in September 1996. It was in the role of CEO that he was credited with turning what he once described as a 'basket case' into a text book example of how a company can turn itself round. Asda has since become both a leading player in its market and is regularly cited as one of the best companies in the country to work for. This success led to the sale of Asda to US retail giant Wal-Mart for £6.7billion in 1999. After the sale to Wal-Mart Allan became the President and CEO of Wal-Mart Europe.
In November 2000 he left Asda and famously coined the phrase ‘Going Plural'. This idea of working full time but not in any one company led to Allan taking on Non-executive roles in a range of companies. He is currently President of Loblaw Companies Ltd, Deputy Chairman of Selfridges & Co and George Weston Ltd, and Non Executive Director of BSKYB Group plc.
In June 2007 Allan's book "On Leadership: Practical Wisdom From The People Who Know" was published by Random House.
In September 2011, Allan's book "'Tough Calls: Making the right decisions in difficult times' was released. Allan is open to doing presentations on this subject.