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AGENT-ORIENTED INFORMATION SYSTEMS ANALYSIS AND DESIGN 101
e.g., Aridor and Lange, 1998) are not intended for use at a design level. Instead, such proposals
seem to aim at the implementation phase, when issues such as agent communication, information
gathering, or connection setup are addressed.
Social patterns in Tropos (Do, Kolp, and Pirotte, 2003) are design patterns focusing on social
and intentional aspects that are recurrent in multi-agent and cooperative systems. In particular,
the structures are inspired by the federated patterns introduced in Hayden, Carrick, and Yang,
(1999) and Kolp, Giorgini, and Mylopoulos (2001). We have classified them into two categories:
pair and mediation.
The pair patterns—such as booking, call-for-proposal, subscription, or bidding—describe direct
interactions between negotiating agents. For instance, the bidding pattern involves an initiator and
a number of participants. The initiator organizes and leads the bidding process, publishes the bid
to the participants, and receives various proposals. At every iteration, the initiator can accept an
offer, raise the bid, or cancel the process.
The mediation patterns—such as monitor, broker, matchmaker, mediator, embassy, or wrapper
—feature intermediary agents that help other agents to reach an agreement on an exchange of
services. For instance, in the broker pattern, the broker agent is an arbiter and intermediary that
requests services from a provider to satisfy the request of a consumer.
Detailed design also includes actor communication and actor behavior. To support it, we pro-
pose the adoption of existing agent communication languages like FIPA-ACL (Labrou, Finin, and
Peng, 1999) or KQML (Finin, Labrou, and Mayfield, 1997), message transportation mechanisms
and other concepts and tools. One possibility is to adopt extensions to UML (OMG, 1999), such
as Agent Unified Modeling Language (AUML) (Bauer, Muller, and Odell, 2001; Odell, Van Dyke
Parunak, and Bauer, 2000) proposed by the Foundation for Physical Intelligent Agents (FIPA,
2001) and the OMG Agent Work group.
We have also proposed and defined a set of stereotypes, tagged values, and constraints to ac-
commodate Tropos concepts within UML (Mylopoulos, Kolp, and Castro, 2001) for users who
wish to use UML as the notation in Tropos.
CASE STUDY

Media Shop is a store selling and shipping different kinds of media items such as books, newspa-
pers, magazines, audio CDs, videotapes, and the like. Media Shop customers (on-site or remote)
can use a periodically updated catalogue describing available media items to specify their order.
Media Shop is supplied with the latest releases from Media Producer and in-catalogue items by
Media Supplier. To increase market share, Media Shop has decided to open up a B2C (business
to consumer) retail sales front on the Internet. With the new setup, a customer can order Media
Shop items in person, by phone, or through the Internet. The system has been Medi@ and is avail-
able on the World Wide Web using communication facilities provided by Telecom Cpy. It also
uses financial services supplied by Bank Cpy, which specializes in online transactions. The basic
objective for the new system is to allow an online customer to examine the items in the Medi@
Internet catalogue and place orders. The main interface of the system is shown in Figure 7.1.
There are no registration restrictions or identification procedures for Medi@ users. Potential
customers can search the online store by either browsing the catalogue or querying the item data-
base. The catalogue groups media items of the same type into (sub)hierarchies and genres (e.g.,
audio CDs are classified into pop, rock, jazz, opera, world, classical music, soundtrack, etc.) so that
customers can browse only (sub)categories of interest. An online search engine allows customers
with particular items in mind to search title, author/artist, and description fields through keywords