No it's an equation but something that seem to confuse a lot organisations. Reading this article from AIIM it shows why you should look at your organisations deployment of MOSS (SharePoint) before considering going all out on an RFP to get an ECM platform.

Topics from the article below:

ECM Only
The first option is to continue with the traditional ECM vendors, such as EMC, OpenText, and IBM (including FileNet). These vendors are proven, scalable, and widely implemented. Most organizations have at least one ECM vendor implemented and many have selected an overall ECM standard. The ECM vendors have traditionally been implemented departmentally, and have frequently been difficult and expensive to implement on an enterprisewide basis. Additionally, it is not clear that they solve all of the ECM requirements of many organizations. In an "ECM Only" solution, the ECM system is the repository of record. MOSS, if implemented, would be a secondary, casual environment where there is no integration or linkages between the two systems.

Read the full article here: http://www.edocmagazine.com/vault_articles.asp?ID=32985