Information Technology Reference
In-Depth Information
presentation layer communicates with the business logic layer, which provides
the services that users require. The business logic layer controls the applica-
tion's functionality by performing detailed processing. Whenever necessary,
it accesses the data layer, where the persistent information of the application
is stored and made available. This layer keeps data neutral and independent
from application servers and from business processes and rules. Giving data its
own tier also improves scalability and performance. The use of this structure
to express a single use case concerned with organizing some logistics support
is shown in figure 4.4.
Figure 4.5 shows a larger part of the software architecture of the PhoneMob
system, described in terms of computational objects interacting at interfaces.
Objects are grouped here in packages for organizational purposes, although the
packaging is not critical: it is mainly used as a reference to identify the separate
layers. The outer packages correspond to the architecture layers. Inside them,
objects are grouped depending on the kind of services they provide. Auxiliary
services (such as login, for instance) have been included because they provide
a set of common functions to the rest of the objects. UML dependencies
between the ports of the UML components that model the computational
object types represent the requirement for bindings between them. Such UML
dependencies are an abstraction of the more detailed way of expressing the
SoftwareArchitecture
HumanObjects
User
RepairCentre
Staff
CourierStaff
ManufacturerStaff
Administrators
....
PresentationObjects
UserInterfaces
AdminInterfaces
GUI2User
GUI2RepairCentre
Staff
GUI2Courier
GUI2Manufacturer
....
ApplicationObjects
BusinessFunctions
AdminFunctions
User
Operations
RepairCentreStaff
Operations
Courier
Operations
Manufacturer
Operations
Login
Function
DataMgmtObjects
Corporation
DataMgmt
RepairOrder
DataMgmt
Stock
DataMgmt
Logistics
DataMgmt
Financial
DataMgmt
HR
DataMgmt
FIGURE 4.5: Part of the software architecture of the PhoneMob system.
