He owned software company Kooijman from 1989 until its sale in 2005 .
Before his appointment as manager in the premier league , Sturkenboom was active for 25 years in IT within the building services engineering industry .
Sturkenboom owned software company Kooijman from 1989 until its sale in 2005 .
Before his appointment as manager in the premier league , Sturkenboom was active for 25 years in IT within the building services engineering industry .