Abstract: There exist massive phenomena of leasing multiple devices at the same time in the real leasing market. And the biggest problem what the manager faces is to optimize the combination of multiple devices on-line leasing in order to reduce the decision-making cost. However, inflation further increases the difficulty. In this paper, risk control model for the multiple devices leasing problem is put forward using the method of on-line algorithm and competitive analysis, and the impact of inflation on decision-making is analyzed. Firstly, the on-line and off-line strategies are proposed respectively for the multiple devices leasing according to the model of Karp's with the factor of inflation. Then to improve the competitive ratio in Karp's model, the risk control strategy which we call the CR strategy is discussed in theory with the hypothesis that the device is continuous separability. Furthermore, when consider that the number of devices investing in real decision-making must be integer, the risk control model is reconstructed and optimized to gain a new approximate strategy-CRJ strategy. Finally, the optimal competitive performance of the strategy is discussed and illustrated by numerical analysis, which shows that the competitive performance of on-line strategy is affected by the fact of inflation and the ways of investing. More, a new idea in multiple devices leasing problem is given in this paper.

Key words: inflation, multiple devices leasing, on-line algorithm, competitive analysis