Optimisation of changes of the operation quality of the transportation system in the fuzzy quality states space

The main objective of the management and control of the transportation system operation is to achieve the highest quality of its operation tasks execution. However, because of the system complexity the accurate determination of the system operation quality is very complicated. To optimize the efficiency of the activities performed to increase the operation quality, it was expressed in the quality states space. In the space the subspaces of the inadvisable, advisable, limited, acceptable and desired quality of operation were defined and the momentary quality of the system operation was expressed in form of the point. Taking into account the subjective character of the survey results and their linguistic inaccuracy the space was transformed into the fuzzy quality states space. Subsequently, the distance between the fuzzy set of the momentary system operation quality and the border of the desired quality subspace was defined. This way, for the quality states not belonging to the desired quality subspace, the minimal changes of the system features required to move this state to the subspace were calculated. The presented in the paper method allows optimizing the efficiency of the activities performed to increase the operation quality of the transportation system. (paper)