Real ITSM's Service Cataract - an essential tool for managing your service portfolio
One of the most important documents in terms of defining the relationship between IT and its customers is the Service Cataract. This lists the available services in terms of their dependencies. The more dependencies there are for a service, the more that a customer will need to put in place first before the service is available.
The optimum position is where a service is dependant on another service or resource being in place first, which in turn has its own requirements and so on through a series of cascading dependencies that pour over the user, hence the term Service Cataract. If properly designed, the Service Cataract can ensure a service is never actually turned on. If the contract is well designed, this will not prevent IT from charging for it anyway.
There are two kinds of Service Cataract:
Naturally the service descriptions in these documents bear little resemblance to each other, but nobody is likely to notice so long as the services have the same name in each.
This extract is from the bookIntroduction to Real ITSM