In the telecommunication (telco) industry, Operational Support Systems (OSS) stands as a back-office system that connects Business Support Systems (BSS) with network elements. As a technical system that provides network service provisioning, OSS operational activities must maintain system availability and reliability. To achieve this goal, it is necessary to have proper and effective communication management planning in operational projects implementation. This research was conducted through a qualitative approach with documentation was sourced from interviews, observations, and lessons learned on the project's internal documents which refer to PMBOK standards. Main results of the communication management plan were communication hierarchy, communication matrix, projects classification, information escalation process, and communication flow. This documentation can be useful for project stakeholders and resources to be aware and prevent failure factors in communication management. Hence, the company or industry can implement effective communication to meet project objectives and achieve project success.