I'm often asked how is Sharepoint different than a BPM Platform? If a company already is invested in it, can they use it to automate business processes and workflows? Here's my view on Sharepoint:
Sharepoint is not a BPMS tool, it’s a content management tool. Fundamentally, it is a content management system (CMS) for organizing information and content in an intranet or extranet. For example, many companies use it for sharing information internally and or with the public. Essentially you can use it to create websites, portals, store and search documents.
After integrating Sharepoint with Visual Studio, Info Path, SQL Server, Workflow Foundation, BizTalk Server and Outlook you can then begin to have a BPMS tool that a developer can begin to work with. It's very complex, resource intensive, requiring high skill sets and is like a development environment as compared to a BPM Platform or Rapid Development environment.
As a result, companies that attempt to implement business process management in Sharepoint find themselves spending a lot of time, money and resources to customize it, dependent on expert developers and with a system that is costly to maintain and improve over time.
As a rule of thumb, you are asking for trouble anytime you try to use a system out of its intended purpose.