Reorganization activities in the enterprise require a systematic approach to assessing the results of particular projects and to forming a portfolio of related projects to implement changes. The systematic approach for business changes analysis involves the consideration of any organizational change in the context of enterprise architecture: it is necessary to take into account the interconnection and interdependence of business processes, organizational structure, information systems, information technology infrastructure and other components. Currently, in order to improve competitiveness and to meet the fast changing business conditions, more and more companies are implementing projects integrating or modifying architectural solutions such as: business process reengineering projects, organizational structure reforming projects, information system implementation, etc. Unfortunately, the problem is often solved separately from the related components of enterprise architecture, which results in unsatisfactory outcome of such projects. Effective implementation of architectural solutions requires a comprehensive analysis of the proposed changes: the reorganization of one of the layers or individual elements of the enterprise architecture entails a change in the requirements for the elements in other layers. The value of the components of the enterprise architecture is defined by a set of services that are provided by these components to each other. Therefore, services are considered to be a universal tool for aligning architectural layers and creating a balanced enterprise architecture. In this paper we formulated a stepwise algorithm of the service-oriented analysis of architecture, defined the methods of service requirement identification and demonstrated the use of the algorithm in a specific project.