AT&T has undertaken a concerted effort to improve customer service at the National Service Assistance Center (NSAC). The benefits have been realized through the use of advanced technologies for assistance in problem diagnosis and information retrieval, tightly coupled with automated customer information access and on-line text and graphic documentation facilities. This paper describes the Trouble Shooter component of the Expert Solutions Platform. The application is a unique approach to developing large case bases; utilizing a templating process which allows a non-technical means of reviewing the large case bases in an environment integrated with a fully functional text and graphic retrieval system. The Trouble Shooter component utilizes Case-Based Reasoning technology to resolve problems and provide information to the AT&T customer support agents for business coimnunications systems. This component has been tightly integrated with the other modules of the ESP system to make the overall platform more user friendly, efficient and provide consistent diagnostic information to resolve the customer’s problem. This enhanced system functionality enables a significant streamlining of the customer assistance process. The Trouble Shooter is currently being used by 150 associates, with deployment underway to additional users.