Abstract
According to the NTT DATA definition, system architecture design is designing optimum hardware and software configuration that is necessary to ensure performance, reliability, availability, etc. of the system delivered to customer. When COE systems headquarters was established in 1999, a method for system architecture design was defined as WBS-based procedures, and then frameworks implemented using the method, which is called recommended solution sets, have been provided to projects. By providing technical support internally for the applied solution sets, the design may be the better. In this paper, the importance of WBS for project manager, IT architect and business consultant, to make their responsibilities clear within the project and project manager concentrates on managing the knowledge areas written in PMBOK, is also introduced.