At the heart of every IT service management practice should be the Service Strategy. Without a well defined service strategy it is very difficult to have any cohesiveness with how your services are delivered and therefore you may find yourself with a hit-or-miss approach to your IT service delivery.
If you find your organisation is delivering IT services inconsistantly or on their "best-effort" then you can almost guaranty that not enough time has been spent thinking about the enterprise service strategy.
You will need to make some decisions around how you want to support each service. Start by defining the services, what value they bring to the organization and how strategic they are to your company's goals.
Focus on the true value of each service. Not just on the dollar value but how poor delivery will affect things like customer relationships, employee moral, reputation, efficiency, safety and security. Without understanding the true value of each service it is hard to make decisions on where you should focus your resources and you will either end up with excessive redundency or lack of capacity to control the service delivery.
Once you have a solid strategy in place you can set the foundation for your service design, transition, operation and ultimately continual improvement.
For more information on IT Service Strategy email firstname.lastname@example.org.