Introduction. The presence of a strategy and a strategic plan, necessary for determining the direction of the enterprise development and for making informed decisions, allows enterprise to achieve its goals with confidence and, at the same time, to respond flexibly to changes in the external environment, especially in times of crisis.Problem Statement. The formation of sustainable development strategies requires sufficient consultancy costs and technologies that are designed for being used by large enterprises with professionals having relevant expertise. However, most of all, during the crisis, small and medium-sized enterprises of the service sector suffer from it, which prevents them from using such consulting and technologies.Purpose. The development of a verbal model for shaping an optimal strategy for sustainable development of small and medium-sized enterprises of the service sector in times of crisis to find, to evaluate, and to support effective management decisions.
Materials and Methods. Methods of formal logic, qualitative methods of verbal analysis, methods of discrete mathematics, and benchmarking method.Results. A verbal model has been developed for classifying the current state of enterprises on the basis of qualitative methods. The model is adapted for the possibility of its use in the presence of an arbitrary set of criteria and their values. A model has been developed for the automatically finding the optimal path (strategy) from a certain alternative (the current state of the enterprise) to an alternative that is guaranteed to belong either to the next better class (short-term strategy), or to the best class (long-term strategy).Conclusions. The verbal model allows us to describe and to classify the states of small and medium-sized enterprises of the service sector in any branch of business and automatically produces optimal strategies for their sustainable development. The criteria for optimal strategy may be the time and cost of achieving the required state of enterprise.