Irvine told the club's official website: "The short term is simple - keep this club in the Championship. We need to have a huge turnaround in terms of the form for the second half of the season and we need the wins.
"So short term, it's exactly the same as when I went in at Preston. I joined them when they were in danger of relegation and I managed to get them out of trouble and get Preston safe with four games to go. I would be absolutely delighted if I could do the same again here.
"Longer term, obviously it is to take this club into the top half of the table and compete at that end. Again, if we could replicate what was done in my second season at Preston, I would be delighted."
The former Everton midfielder added: "Everybody in football knows that this is a fantastic club and a club with enormous potential. When you're at other clubs, you always keep an eye on clubs like Sheffield Wednesday because of the tradition and history of the club. They have fantastic support and this is a great opportunity for me."
Source: Team Talk