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The Best Way to Define IT Services

Jan 16, 2008

Hank Marquis

For Example

Let’s consider the ubiquitous IT service usually called something akin to “email”, although it may go by the name Exchange, Outlook, Notes or even “Communications Services.” Few IT services engender the passion, debate and paralysis of trying to decide if email is a service or not, so it’s a good example. Be sure to keep in mind the SID three layer model and the easy rules of “perception during use” and “ability to acquire.”

Your customers use CFS to deliver enterprise products. If your company manufactured widgets, then your IT service customers might use the “Email Send and Receive” CFS in pursuit of selling and supporting widgets. A optional CFS may be the ability to include file attachments when sending and receiving emails, yet another optional CFS may be the ability access email via broadband or dial connections. In this example, three CFS might combine to create a service.

Such an email service could include either of the optional CFS, both of them, or none of them depending on what your customer chooses. Conversely, the IT service provider (you) might decide to offer all three example CFS as a single bundled CFS called, you guessed it, “email.”

CFS are defined as those IT services a customer may acquire directly from an IT service provider. Customers are aware of and interact with CFS, and one or many CFSs normally underpin or create one or more business processes and products. CFSs consist of RFSs, and RFSs may not be acquired by a customer except as part of a CFS.

Consider the ability to send and receive emails, which requires routing and transmission services not available and probably not useful to a customer outside of their incorporation into CFS. For example, the CFS of “Email Send and Receive” might not operate without the RFS of “Domain Name Services” (DNS) and perhaps the RFS of “Dynamic Host Configuration Protocol” (DHCP.) Customers are usually unaware of RFS since they do not acquire or interact with them directly. RFS are usually shared IT services and underpin one to many CFS.

RFS, for example DNS or DHCP, consist of one or more IT resources. For example, individual network links, Internet routers, servers, software, support technicians, operating procedures, etc., all combine together as a RFS (perhaps DNS or DHCP in this example), which is not only unavailable directly to the customer, but of which the customer may be totally unaware and unable to use outside of its CFS.

RFS create CFS and IT resources create RFS. IT resources consist of all the individual information, technology, capital, accommodation, human and other related components required to produce and support RFS. IT resources underpin RFS, and most IT resources are shared across several and in many cases all RFS.


So there you have it. Honestly, this is the simplest and easiest to understand taxonomy for IT service definition I have every seen or used, and I have seen and used quite a few. I think the most elegant, fastest and easiest way to define IT services is without a doubt SID. Using this methodology you should be able to define your services in hours instead of weeks.

The beauty of SID is that is over 100 years in the making and has been validated by telephone, operating, cable and other IT service companies the world-over. In summary:

  • CFS create or support products;
  • RFS create or support CFS; CFS and RFS are “back to back”;
  • Resources create or support RFS; and
  • Resources are single purpose technology bits like routers, switches, computers, etc.
  • I can’t tell you why ITIL doesn’t reference SID, but I can tell you that SID is simply the best way to define IT services. Check it out, you will come to think so too.

    Hank Marquis is director of IT Service Management Consulting at Enterprise Management Associates based in Boulder, Colo. Marquis has more than 25 years of hands-on experience in IT operations, management, governance and operational frameworks. Visit his blog and podcasts at www.hankmarquis.info.