Because of the System Architecture is based on the structure of the entire system. Displays the components and the relationships between those components, Understand the key elements and the relationships between those elements. Focus on the key points that affect the overall system. Both in terms of function and quality. Must comply with the concern of the stakeholder architect to use architecture is designed to communicate with stakeholder to provide stakeholder comprehensive overview and guidelines ( solution ) the architect to handle the concern and to share analysis assessment. and revision, which may be fine for some revisions. In order to stay in the concern and constraints and then led the architecture to implement the model in the next post . Architecture is useful for other things such as the system administrator, system updates, etc.