This paper presents a decision-support model identifying the most viable ice class for a liner vessel transiting along the Northern Sea Route. As input, this model requires parameters, some of which are uncertain. These include the time-dependent length of the Northern Sea Route sailing season and corresponding roundtrip times, the additional capital expenditure and operational expenditure for ice class capabilities for the vessel, as well as fuel price. Furthermore, the sensitivity of the model is discussed on the perspective ice extent, respectively the ice class allowed to enter the Northern Sea Route and possible delays, on the basis of current trend predictions.