In this paper, we investigated issues of arctic supply vessel design and fleet composition. Analysis of factors of various nature that influence the performance of the Arctic supply system, as well as exploration the possible ways to improve its efficiency are presented. For addressing this we developed a research approach that joins the holistic parametric design model of arctic supply vessel and the fleet planning algorithm. The last one solves the fleet sizing problem and simulates the dynamics of vessel operation, ice state and logistics features of platform operation. We presented the results of system performance analysis for the case of supply fleet operation in the Kara Sea. Factors under investigation were ice class, deadweight, ship type, the structure of cargo-flow and distribution of useful hull capacity by cargo type. The article provides the recommendations on the formation of the offshore supply system based on the studied case. This confirms the usefulness of the proposed approach for handling the considered problem.