Nowadays, the airlines use discrete optimization in many fields in order to plan and control resources like crews and aircraft. The biggest recent problem is a growing number of delays and delayed flights what significantly increases operational costs and harms goodwill of the airline. Therefore growing importance lies in robust optimization that can provide more stable solutions, with respect to delays, so to minimizes operational costs of the airline. In our project, we focus on one part of the planning, namely on Tail assignment.