The paper investigates the existing software change management approach at Tele2 and uses accumulated experiences as a basis for conceptualizing the planning of changes in packaged applications. Tele2 is one of Europe's leading telecom operators, offering mobile services, fixed broadband and telephony, data network services, cable TV and content services with 37,6 million customers in 11 countries. IT operations and services are being supported within Tele2. Change management, especially scheduling of changes, is known to be one of the most challenging problems in managing of IT operations. The task of finding an optimal change implementation plan is difficult considering many variables which influence the decision on resource allocation to implementation of change requests. Many IT companies do planning manually, re-allocating and re-planning resources constantly. This paper presents the results from in-depth study of change management and planning practices with the aim to identify concepts and their attributes influencing the change implementation plan. The conceptual model is elaborated based on the collected concepts. The objectives of change planning such as implementation cost and time minimization are also represented in the conceptual model. The one of the most important features represented in the conceptual model is re-planning of change implementation activities in response to changing development priorities and external events such as new updates of the packaged software. The conceptual model and concepts are validated against four similar studies. Construction of the conceptual model also allowed to identify several directions for future improvement of change management and scheduling practices. The described conceptual model will serve as a basis for further work on design and implementation of change planning decision support system.