In organizations where multiple Organizational Units (OUs) or departments wish to use Microsoft Project Server 2010 to manage their work, the question often arises:
Should each Organizational Unit, Business Unit, or Department use their own Project Server instance, or should they share?
Although some Project Server implementers have strong opinions in this area, I suggest that there is no best option for every situation. Every organization has different needs; some are best served by having separate Project Server instances, and others are best served by a shared Project Server instance. Some organizations may even have a need to install, configure, and maintain a completely separate SharePoint farm for different OUs. Here is my attempt at explaining each option, its implications, and its pros and cons.
Overview and Terminology
A SharePoint Farm is a group of one or more servers, either physical or virtual, that work together to host the SharePoint application and any services running inside that application, including Project Server. A farm may consist of a single server that does all the number crunching and responds to all user requests, or it may consist of several servers that work together to share the workload. The end users are generally oblivious to the number of servers in the farm that are processing their requests, since they simply access the application (i.e. SharePoint, Project Server, etc.) through a single URL (i.e. http://mycompanyportal).
It is generally recommended to set up a SharePoint farm with at least two servers (one holding the databases and another hosting the SharePoint Server & Project Server applications); however, a very small organization may only need a single server, and a larger organization may have several servers in the farm to share the workload of hundreds or thousands of people using the system.
A single-server farm processing requests from people at computer workstations:
A multi-server farm with servers working together to process requests from people at computer workstations:
A Project Server Instance is a web-based application that can store and display projects and resources, communicate task assignments to Team members, capture task progress from them, and perform a wide variety of other functions for people within an organization. If you compare it to another very widely-used web-based application, Facebook, you will see some similarities. For example, a Project Server instance has a web interface accessible via your Internet Explorer web browser, Project Web App (or PWA), as does Facebook (http://www.facebook.com). A Project Server instance also allows you to interact via client applications such as Project Professional, as does Facebook (i.e. mobile apps for your Android tablet, iPhone, or Windows phone). The Facebook web-based system does not run on a single web server, but rather it runs on a farm of many servers working together to handle the heavy workload of hundreds of millions of people around the world.
Similar to how a shared web server may host multiple of web sites on the World Wide Web, a SharePoint farm can host one or more Project Server Instances for an organization. If multiple OUs within an organization (i.e. Engineering, Marketing, IT) wish to use Project Server, then they may share a single Project Server instance or they may each choose to deploy their own unique Project Server instance. Just as a web site on the World Wide Web appears to be completely independent of all other web sites on the web, each Project Server instance appears to be completely independent of any other Project Server instances, even though they may all be hosted within the same SharePoint farm.
Multiple OUs sharing a single Project Server instance:
Each OU using their own independent Project Server instance:
Each Project Server instance has its own PWA web site with its own unique URL (i.e. http://mycompanyportal/pwa, http://mycompanyportal/engineering, http://mycompanyportal/marketing, or http://mycompanyportal/it), its own set of project- and resource-related data (project schedules, resources and users, timesheets, status reports, etc.), and its own unique configuration. Each Project Server instance in a SharePoint farm has its own set of four Project Server databases to store its project and resource-related data, and the instances may share a single SharePoint Content database which stores other project artifacts such as documents, issues, risks, and deliverables, or each instance may have its own SharePoint Content database.
Following are the main three options available for multiple Organizational Units wanting to use Project Server 2010, as well as a list of pros and cons for each; you may encounter the occasional situation where a hybrid approach is necessary, but these options should give you enough information to make your system architectural design decisions:
Option 1: Each Organizational Unit or Department Uses Their Own Project Server Instance
As stated previously, this option involves provisioning a separate instance within the SharePoint Farm for each OU.
Option 2: All Organizational Units or Departments Share a Single Project Server Instance
As stated previously, this option involves provisioning a single shared instance within the SharePoint Farm for all OUs.
Option 3: Each Organizational Unit or Department Uses Their Own SharePoint Farm
I would be remiss if I did not mention this option, although implementers typically do not select it except in somewhat rare cases. This option involves provisioning a separate SharePoint farm with one or more instances for the OUs. This type of system architecture is sometimes used if there are multiple IT groups within an organization, each will manage their own separate farm, and each has a separate set of OU customers that they service.
This type of system architecture may also be used in highly secure environments with completely separate networks within the organization. For example, one farm may be on a highly secure network and another farm may be on a less secure network that personnel with lower levels of security clearance will access (i.e. vendors or personnel who have not been granted higher security clearance). Any data that is transferred between the two systems may need to be copied to a removable drive and physically moved to a machine on the other network!
Please remember that although Option 1 seems to have the best ratio of pros to cons, every organization has different needs. Evaluate your organization's needs, refer to the pros and cons of each option, and make an informed decision for your situation.
Anything to add? Do you have real-world experiences to share? Please tell us by leaving a comment.