The subject matter of the article is methods and approaches to software modeling of System of Mass Services on the example of a multi-channel system with a limited queue and failures in case of its overflow. The goal of the work is to justify the feasibility of using modern computer information technologies, namely the Go programming language for modeling System of Mass Services. The following tasks were solved in the article: formulation of the researched System of Mass Services; determination of components, criteria of kinship of System of Mass Services with their software models; general overview of concurrency as a mathematical model; a description of the approaches and tools of the Go programming language. The following methods are used: Go programming language and its tools, concurrency, parallel execution. The following results were obtained: the researched task of mass service was formulated; criteria for comparing the components of System of Mass Services with the Go programming language toolkit were formed; an analysis of the feasibility of using the Go programming language for modeling System of Mass Services was carried out; received further development of tools for computer simulation of System of Mass Services; the application of concurrency approaches, their implementation in the Go programming language, to the modeling of System of Mass Services is proposed. Conclusions: The Go programming language is a very successful technology for modeling System of Mass Services. Its philosophy, way of working, as well as the built-in toolset provide ample opportunities for modeling various System of Mass Services. The use of this language is appropriate and allows to bring the behavior of the program closer to the simulated process, simplify implementation, and reduce the time required for data processing. There are great prospects for the further implementation of a software product implemented in the Go language in the field of mass service process modeling.