Three important groups of users can be distinguished when it comes to creating workflows: knowledge workers, site administrators and Web designers, and developers. The following list describes the most likely division of responsibilities of these groups:
Knowledge workers. This group of users consists of people who will create ad hoc workflow solutions based on the predefined workflows already available in SharePoint Designer 2007. The complexity of these workflows will be low.
Site administrators and Web designers. This group will use SharePoint Designer 2007 to create custom workflows for a specific list or library. The complexity of such workflows will be average.
Developers. Developers will primarily use Visual Studio ...