The Swiss outfit endured a disappointing Formula 1 campaign and subsequently finished last in the constructors' championship with a paltry five points.
Vasseur claimed that their difficulties stemmed from the problems in the previous year when they almost folded due to financial problems.
Sauber were rescued by a consortium linked to driver Marcus Ericsson, but their plans for 2017 started late and that had a knock-on effect going into the season.
But with work well under way with the 2018 car and a new multi-year partnership with Alfa Romeo, the Frenchman is hopeful of a better performance this time around.
Vasseur said: "Now we have a brand new project. Sauber started very late last year, but the 2018 project is on schedule.
"But of course only the first test in Barcelona at the end of February will tell us where we are."
Formula 2 champion Charles Leclerc will also partner Ericsson after previous driver Pascal Wehrlein was axed and, he added: "Yes, there are many expectations and I think we have made some strong choices. Above all with the engine - having the 2018 Ferrari engine will mean a big step forward for us. And we have started with a new philosophy for the car."