One of the biggest fears of business unit managers when discussing the move to Shared Services is that they'll lose control of their processes to a bureaucratic nightmare.  And it is not completely unfounded.  For too many years corporate services has provided too little value for too much cost.

While a Shared Service Organization can take serve their business units in a variety of ways, there are some essential elements that must be incorporated to ensure long-term responsiveness to the business units and to ensure that the Shared Service Organization is focused on those activities that are truely valued by the business.

1. Implement a sound governance structure that properly represents business unit interests.  Having the appropriate level of business unit representation will go a long way to ensuring the the SSO understands and is meeting the needs of the business.  These BU representatives should have strong organizational and political authority to represent the business.  Business Unit representatives should be high enough in the organizational hierarchy that they are taken seriously.
2. Clearly define what success looks like.  There should be clearly defined metrics that measure specific goals, such as cycle times and costs.  There should also be clear agreement with the business on how these metrics are collected, and how often, so that there aren't arguments over who's data is correct.
3. Regularly reevaluate what has value for the business.  As a general rule, business units value analysis and insight over pure transaction processing; however, that isn't to say that transaction processing isn't important.  It must be done efficiently and with sufficient control to maintain integrity of financial and management information.  But if the SSO is cranking out a monthly management reporting package that no one uses, then the business units has not only spent money needlessly, but they have been deprived of the time spent that could have been allocated towards value-added activities.
4. Regularly reevaluate the organization structure and responsibilities of the Shared Services Organization.  Markets and businesses change over time.  And these days that happens much faster.  As 3rd party service providers mature, it may make sense to move activities out of the captive SSO and to these 3rd party providers.  Or maybe it makes sense to move an activity back to the business units if the goals for that process haven't been reached after a set amount of time.  The point is that nothing stays the same, and Shared Service Organizations should constantly be looking at how they can reinvent themselves.

By focusing on these four areas, the captive Shared Service Organization can ensure that it remains relevant to the needs of the business it's serving.