Sommerville-Software-Engineering-10ed

474 Chapter 16 ■ Component-based software engineering
CBSE processes
Domain analyst,
Designer,
Implementor,
Maintainer,
Market analyst
CBSE for
reuse
CBSE with
reuse
Component
acquisition
Specifier,
Designer,
Integrator,
Maintainer
Librarian,
Vendor,
Broker
Component
certification
Component
management
Librarian
External
source
Local or
external
certifier
Component
repository
Figure 16.6 CBSE
processes
2. Component management is concerned with managing a company’s reusable
components, ensuring that they are properly catalogued, stored, and made available
for reuse.
3. Component certification is the process of checking a component and certifying
that it meets its specification.
Components maintained by an organization may be stored in a component repository
that includes both the components and information about their use.
16.2.1 CBSE for reuse
CBSE for reuse is the process of developing reusable components and making them
available for reuse through a component management system. The vision of early
supporters of CBSE (Szyperski 2002) was that a thriving component marketplace
would develop. There would be specialist component providers and component vendors
who would organize the sale of components from different developers. Software
developers would buy components to include in a system or pay for services as they
were used. However, this vision has not been realized. There are relatively few component
suppliers, and buying off-the-shelf components is uncommon.
Consequently, CBSE for reuse is mostly used within organizations that have
made a commitment to reuse-driven software engineering. These companies have a
base of internally developed components that can be reused. However, these internally
developed components may not be reusable without change. They often include
application-specific features and interfaces that are unlikely to be required in other
programs where the component is reused.