The Tractor Boys have failed to reach the playoffs within the seven seasons that Evans has been at the helm.
Evans told BBC Radio Suffolk: "When I first bought the club I did expect it to happen far easier.
"Those people who sold the club did a very good selling job in persuading me that a little bit of extra money and one or two extra players was all that was needed.
The businessman, who bought the majority stake of the club in 2007, is currently working with his fourth manager in the form of Mick McCarthy.
Ipswich won their first match in the new Championship season 2-1 against Fulham on Saturday.