Network slicing is defined as one of the main components of fifth-generation mobile communications that can solve the problem of colossal growth in data volume traffic in cellular networks. This paper reveals the concept of the probability of slice degradation as the example of a model built using a retrial queueing system. First, we build a mathematical model, for defining of the degradation probability, then we analyze it using the example of two tenant case. The purpose of this study is to develop a framework that will allow the infrastructure provider to calculate such bandwidth thresholds for each slice which do not violate the requirements for the probability of degradation and maximizing the revenue from the tenant. © 2021, Springer Nature Switzerland AG.