IT project management can use both project and process-oriented approaches. Pre-investment, investment (development and implementation phase), and operations and maintenance are the three phases that make up the life cycle of an IT project. The service processes are part of the third phase. The earliest stage of an IT project's life cycle necessitates a substantial financial commitment. As a result, it may be considered a business venture. As a result, project management concepts and techniques may be used in the implementation of IT projects. During the investment phase, methods for software development and testing are implemented. It is carried out in compliance with industry standards that govern the deployment of life cycle models. The size of the program code and the complexity of the software determine the cost and timeliness of IT system implementation, maintenance, and servicing jobs. As a result, the process approach can be used to manage various phases of large-scale IT projects. Supply chain optimization, in particular, can be used advantageously. This report is devoted to the optimization of supply chains for service operations at the stage of implementation and maintenance of large IT projects. A feature of this approach is that the human resources of an IT service support team are considered as a subject for the supply chain. Conditions are also given that the supply chain for service operations considered has the resilience and viability properties. The parameters for the multiple-channel queuing model are calculated using the mathematical model presented in this paper. Microsoft Excel is used to implement this model. It enables us to generate estimations for the average time of maintenance and support jobs during the pre-investment phase, as well as determine the optimal size for the IT service support team.