Page 455 - Handbook of Modern Telecommunications

3-246 CRC Handbook of Modern Telecommunications, Second Edition

customer orders to fulfilling the orders and maintaining the resources. Assurance ensures that the ser-
vices and resources are working as they should and the business and customer expectations are being
met. Usage supports the processes responsible for collecting information about, and understanding
how, services are used and creating the billing and business intelligence information from that data.

3.10.4.1.5 Other Lifecycles
There are other lifecycles that occur within a business and within a service provider beyond the three
we have considered so far. For example, the relationship that a service provider has with their custom-
ers goes beyond what is captured by the service subscription lifecycle. One could talk about a customer
lifecycle that drives the broader relationship and may contain within it multiple instances of the service
subscription lifecycle (i.e., a customer subscribing to multiple independent services).
On a different level, we can also look at lifecycles such as the service session lifecycle: the initiation,
use, and termination of a particular session by a customer (e.g., placing a phone call or watching a
movie). A typical service subscription lifecycle would include multiple service sessions. This provides
the distinction between, for example, having telephone service (service subscription) and making a
telephone call (service session).
While these other lifecycles could be vital for the enterprise, we do not consider them here because
they only loosely affect the OSS.
3.10.4.1.6 Interactions among the Lifecycles
The three lifecycles are not independent of each other—links exist between them. For example, the decision
to introduce a new service offer may require major enhancements to the infrastructure in order to support
the service. That would drive requirements that would be implemented thought the resource lifecycle.
An interesting link is that between the service instance and the resources. Traditional services have
a very direct link between these two since the services have dedicated resources. As the world evolves
to include new services provided through shared infrastructure, such as packet-switched networks
and VAS services provided through traditional IT systems, the link between the service instance and
the resource is becoming increasingly virtualized. This, in turn, introduces abstractions to the links
between the service instance lifecycle and the resource lifecycle.

3.10.4.2 Fulfillment, Assurance, and Usage
The ITU defines five management functional areas [M3010]: performance management, fault manage-
ment, configuration management, accounting management, and security management (usually abbre-
viated as FCAPS). While this view of the functionality provides value at the element management layer,
the abstractions defined by the TMF are more appropriate at the business process layer. The TMF talks
about fulfillment, assurance, and billing (FAB). As we see in the following, it makes sense to expand this
to fulfillment, assurance, and usage.
In addition to the three functional areas, we need to introduce functionality that is common across all
three areas. We call this the OSS/BSS Integration area. Figure 3.10.2 illustrates OSS functionality.

OSS/BSS Integration

Fulfillment Assurarnce Usage

Converged telecom and IT infrastructure

A high-level view of the OSS functionality
FIGu RE 3.10.2 A high-level view of the OSS functionality.