Today, one of the biggest challenges faced by Enterprise is strategic alignment of information technology with business; and Enterprise use various methods to achieve this strategic alignment. Enterprise architecture is an effective approach that allows optimal management of Enterprise’s information technology and strategic alignment of IT applications and business requirements. But the question is whether only implementation and running of Enterprise architecture resolves this challenge? Considering today’s dynamic environments, there is the possibility of any kind of change in Enterprise’s conditions, especially after implementation of Enterprise architecture. This change of conditions manifests itself in a variety of ways. In these cases, decision making should be done as appropriate to these changes, and an appropriate response to the changes should be predicted, since otherwise it would lead to lack of proper response and thus readjustment of Enterprise architecture document, which imposes many human and financial costs on the Enterprise. In addition, the Enterprise’s progress toward competitive advantages will be stopped. The response and adaptability appropriate to these changes is a concept represented under the title of adaptive maintenance of Enterprise architecture. In the present study, with the help of a software maintenance method and examining the possibility of generalizing it to Enterprise architecture maintenance, through a case study on Power Distribution Company of Golestan province, we show how we can assist improvement of adaptive maintenance of Enterprise architecture and provide the possibility of implementation of various types of changes in business and information technology without disturbing the Enterprise.