If you look at the descriptions of Critical Success Factors associated with ITSM adoptions, the first one on almost any list is Management Commitment.
Sounds good...until you try to figure out exactly what that means...
Management Commitment is more than just the willingness to train people, or buy software, or even have big Communications strategies about how important ITIL is...it's the willingness to BE committed. The best way to actually measure this is willingness to sign up for roles like process and service owners. In order to ask for accountability from IT teams and to employ meaningful governance and oversight of Service Management, the senior managers (with enough authority to enforce commitments) must be willing to commit themselves as well. IT staff notice when senior teams make real commitments, and will align their efforts accordingly.
I recently watched a short promotional video from one of the major ITSM vendors (I'll protect the guilty, but you can find it quickly if you look). It depicts a CIO describing the value of Business Service Management, and includes a roundtable with his senior IT staff. Ironically, the copy from the video is more typical than ever.
"I think we should tell the IT staff about the commitments I made on their behalf, so they know what I need them to do."
Can't get buy-in that way!
If you want IT organizations to commit to Service Management, IT leadership has to commit itself to processes like Service Level Management, which prevent "free lunch" behaviors and encourage the business to work cooperatively with its customers to evaluate evolving requirements against achievable targets. This involves listening to both clients and IT teams, and working to establish collaboration that focuses on the business value of the outcome, not only "do more with less."
CIOs need to focus on business outcomes, and then work closely with their teams to support the optimal level of service to meet those needs, balancing cost/value. Taking specific service ownership of a key business service (perhaps, say, an online marketplace critical to sales growth) and taking specific accountability for service outcomes related to that service will raise the game a great deal, and drive the interest in metrics, continual service improvement, and ultimately business results. Once a CIO signs up for the most mission-critical one him- or herself, it's a lot easier to get other senior managers to sign up for other services, and really establish cross-functional "service views" of the world.
Management Commitment is good talk, but, most of the time, talk is cheap. If you want to see results, demand real commitment, and real action. It will help you dramatically improve your results!