I get asked lots of questions about SharePoint. One of the harder ones to answer is “how many site collections do we need?” Why?... because, in my opinion, there is no right answer. SharePoint implementation is a very personalized experience where you, as a member of the implementation team, make many choices of what functionality to use (or not use) and to set a definition for how it should be used. Determining the appropriate number of site collections is (or should be) dependent on the choices you make in your information architecture and, in some ways, will ultimately depend on the bias of the information architect(s).
Never one to shy away from a question, I answer in the following way…
Your decision on site collections will depend on your SharePoint knowledge. This is split into two main categories, technical and tactical. Technical knowledge is defined by terminology and concept information that you might find in places like here. It sets the basis for understanding the limits of functionality within and across site collections. The second is tactical and is focused on your business users. It sets the basis for understanding how information workers in your environment best work and adhere to structure (including content organization, navigation, branding, and search). The cross-section of these two help define your site collection roadmap (I use the term ‘roadmap’ to emphasize the need to consistently evaluate your information architecture and course correct – add/consolidate site collections as an example – as needed). Remember, there is no “right” answer but your users will most certainly tell you implicitly or explicitly if they think you got it wrong.
When I lead a design session and we talk about site collections I lay out for discussion the items listed below. In the case of an intranet design, I always start with two site collections (one for corporate content, one for ad hoc collaboration), walk participants through the technical and tactical decision points, and challenge the default design until we get to a comfortable place. This is a very interesting experience as we often find that one item, navigation for example, will sway the decision making. Sometimes, we end up with one site collection; often times, it is two or many more… but I NEVER set the number until we get to the appropriate level of detail to make an educated choice.
So, sometimes I answer “how many site collections do we need?” with another question “how many site collections do you think you need… and why?”
· Quota
· SharePoint security groups
· Branding
· Site columns
· Navigation
· Search
· Backup/Restore
· Features
· Distributed site collection administration
· Security
· Governance
· Service Level Agreement (SLA)