Birmingham City's board knows they must improve in every area of the pitch if they're to survive in the Premiership.
"We want to strengthen the team in every department, subject to the financial restraints that we've got," Sullivan told the Sunday Mercury.
"We will push things to the boundary of what we can do and what the club can afford. We hope to have a team out there on August 15 that will compete, not just to keep us in the Premier League, but to turn over some big clubs.
"We feel we have to strengthen the defence and we have to strengthen the forward line to score more goals. That is what we are concentrating on doing, we want to bring in a few players that will excite the supporters.
"Statistically things are tough for promoted sides, but we've been there five seasons. We stayed up in three of the five. It's a tall order and I would tell everyone to be patient with the team because when you bring in a lot of new players sometimes they take time to settle."