The proposal of this paper is to analyze the airlines maintenance planning processes in a merger environment, in order to propose a method that enables the construction of a single process. The methodology used was a case report. The competition between companies is increasing by the globalized world, consequently process management and planning become strategic for the company to remain competitive. In this globalized world is also increasingly the amount of cases of merger and acquisitions. In this context, the present paper analyzes the definition of the airline maintenance planning processes in a moment of merger, with the purpose of recommending a method that guarantees the efficiency of the unification of the processes. The result of the analysis confirms that it is possible to define a successful method for an aircraft maintenance planning processes in a merger case. The method is composed of four steps, definition of culture, involvement of top management, process mapping and process definition.