Harrison replaces Harpreet Kaintel, who has been promoted to chief information officer for the region. Alam's position is a new role designed to help drive the group’s ambitious growth plans.
Both will report to APAC Chairman Gerry Boyle.
Harrison joins from Mindshare, where he was regional head of invention. He led comms planning and the development of creative media strategies for clients including Unilever, Nestle, Kraft/Mondelez, Pepsi and GSK. He has also worked for Leo Burnett and Grey Interactive.
Boyle called Harrison a "brilliant thinker with a unique perspective on the business of brands and consumers", adding that he brings great depth of knowledge and experience in innovative strategy and planning processes.
For his part, Harrison said he was inspired by Boyle's determination to transform ZenithOptimedia to take it to the top in Asia while challenging "the establishment".
Alam will be responsible for creating new business and organic growth strategies, will have input into M&A activity and will continue the development of the ZenithOptimedia’s digital strategies and capabilities, according to the agency.
He joins from a company he founded, Resultrix, which he sold to Publicis Groupe in 2012. He has spent the last 10 years consulting on digital strategies in the banking, insurance, travel and technology sectors.
Boyle praised Alam as a "proven entrepreneur" and "digital evangelist" with an instinctive understanding of how to create success. "He’s just what we need to help deliver on the exciting development opportunities we see in the region,” Boyle said.