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of the product's requirements. From an engineering point of view, there will be
correspondences at a broad functional level, but there is not much of an issue
here because the details of the product's engineering will be largely hidden
from the users. The focus is on the support of the product's interfaces.
The introduction of COTS products will also impact the tool chain; there
will be a need for tools to police all these new relationships, and for them to
provide planning support for the supplier's commitments about the evolution
of the product.
12.3 Competing Sets of Viewpoints
So what happens if both the producer and the user of a component are
using ODP? They will each have a set of viewpoint specifications, but are
these aligned with one another? Each of a set of viewpoint specifications
contributes to a complete and consistent system specification. That is to say,
the set is concerned with the capturing of different stakeholder concerns, but
they are unified by being concerns about a single target system.
When two independent groups specify different systems, they each define
their own logically distinct viewpoint specifications. If the two groups are
operating within the same organization, the enterprise specifications may be
quite similar, but the emphasis and level of detail applied to particular aspects
will differ, and some features in one of the specifications may be omitted as
irrelevant in the other. Indeed, as we saw when discussing federation, one of
the problems in establishing interoperability between systems is that each of
the systems works with a view in which the other is expressed in quite abstract
terms as part of its environment.
The key point here is that the content and level of detail in a specification
is determined by the role the system is to play. If the system is to interact
with some other system in its environment, it is necessary for the nature of
these interactions to be expressed. If the system is to act as an intermediary,
perhaps receiving a reference in one interaction and passing it on to a different
partner in another interaction, then the details of the object referred to are
not of concern to the intermediary, so long as the reference type is correct and
any assertions about the quality of the object referred to are fulfilled. Again,
it all comes down to satisfying the stakeholders' concerns.
12.3.1 Applying Viewpoints to Components
The analysis of incorporation of COTS components can be quite confusing
because the specification of a component required to provide services exists
in parallel with one or more specifications with broader scopes, each of which
describes one way it is to be used.
