To access SSAS, you must first install the SSAS client. For example, 2000 (version 8) from Pivot Table Services install or 2005 (version 5) from OLE DB 9 installer. The other pre-requisites are:
Install and configure Oracle's Hyperion Reporting and Analysis
User authorization for Web Analysis
Access to Microsoft SQL Server Analytic Services as a data source
Access to the SSAS database and/or your own database