Establishing Enterprise Architecture Office for the Public Pension Agency (PPA) using The Open Group Architecture Framework (TOGAF), to increase interoperability, to improve the quality of the work procedures and to support governance and services integration. This paper highlights the main challenges while establishing the Enterprise Architecture office (EA) and move the office from establishment to operations. One of the challenges was to change employee's mind-set. It is totally new idea that there is an office will be responsible for Information Technology Governance, Architecture decision, Lead Information Technology Strategy and innovation while covering the main four domains business, information, application and technology according to TOGAF framework which was adopted by the office. In addition, there was a challenge to capture and document the current architecture and develop the future state and document it professionally using a specialized tool to support the EA in decision-making