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AGENT-ORIENTED INFORMATION SYSTEMS ANALYSIS AND DESIGN 109
Figure 7.7 Decomposing the Store Front with Social Patterns

Shopping
Cart
Handle Provide
Cancelation Item
Request Data
Monitor Notify
Info Update
Broker Fwd Source
Change
Advertise
Source
Location Translate
Profile Query
Customer Response
Locate Mediator Information Wrapper Product
Source Source Database
Provide
Information
Source Route Info Ask for
Info
Matchm. Request Advertising
plug-ins represent a certain risk to the system and the information it manages. Equally important
are the procedures checking the consistency of data transactions.
In the structure-in-5, checks and control mechanisms can be integrated at different levels assum-
ing redundancy from different perspectives. Contrary to the classical layered architecture (Shaw
and Garlan, 1996), checks and controls are not restricted to adjacent levels. Besides, since the
structure-in-5 permits the separation of process (Store Front, Billing Processor, and Back Store)
from control (Decision Maker and Monitor), security and consistency of these two hierarchies
can also be verified independently.

Availability

Network communication may not be very reliable, which can cause sporadic loss of the server.
There are data integrity concerns about the capability of the e-business system to do what needs
to be done, as quickly and efficiently as possible, in particular about the ability of the system to
respond in time to client requests for its services.
The structure-in-5 architecture prevents availability problems by differentiating process from
control. Besides, contrary to the classical layered architecture (Shaw and Garlan, 1996), higher
levels are more abstract than lower levels: lower levels only involve resources and task dependen-
cies while higher ones propose intentional (goals and softgoals) relationships.

DETAILED DESIGN

Figure 7.7 shows a possible use of the patterns for the Store Front component of the e-business
system of Figure 7.6. In particular, it shows how to realize the dependencies Manage Catalogue
Browsing, Update Information, and Product Information from the point of view of the Store Front.
The Store Front and the dependencies are decomposed into a combination of social patterns (Do,
Kolp, and Pirotte, 2003) involving agents, pattern agents, subgoals, and subtasks.
The booking pattern is applied between the Shopping Cart and the Information Broker to re-
serve available items. The broker pattern is applied to the Information Broker, which satisfies the
Shopping Cart’s requests for information by accessing the Product Database. The Source Match-