The second case study developed is the OnLine Intelligent Services (OLIS). It is a MAS-PL that allows the derivation of web applications that provide personal services for the users, such as calendar. The product line was developed using a reactive approach: first, we developed a SPL with an alternative feature, and incrementally we added new optional agent features to this SPL. These new versions of the SPL are characterized as a MAS-PL, because they address new agent features, which allow providing different customized products that have software agents on their architecture. One main difference between the EC and the OLIS MAS-PL development is that the EC had different system versions and later these versions were used as a base for the MAS-PL construction; on the other hand, OLIS was initially built as a product line, and the product line evolved, through the incorporation of new features.

OLIS Overview

The OLIS case study is a MAS-PL of web applications that provide several personal services to users, developed using a reactive approach. The first version of the product line is composed mainly by two services: the Events Announcement and the Calendar Services. However, the OLIS was designed in such a way that it can be evolved to incorporate new services without interfering the existing ones. Additionally, OLIS provides an alternative feature: the event type, thus derived products can deal with generic, academic or travel events.

The Events Announcement service allows the user to announce events to other system users through an events board. The events have some common basic attributes, such as subject, description, location, city, start and end dates, frequency that it happens, and some specific attributes according to the event type. The Calendar service lets the user to schedule events in his/her calendar. Besides the information of the events published in the events board, calendar events have a list of users that participate in it. Announced events can be imported into the users' calendar.

After developing the first version of OLIS SPL, we have identified that new autonomous behavior features could be introduced to automate some tasks in the system. So, we evolved it, incrementally adding new features, which take advantage of the agent technology. The new features incorporated to the OLIS first version are:

  • Events Reminder. The user configures how many minutes he/she wants to be reminded before the events, and the system sends notifications to the user about events that are about to begin;
  • Events Scheduler. When a user adds a new calendar event that involves more participants, the system checks the other participants' schedule to verify if the event conflicts with other events. If so, the system suggests a new date for the calendar event that is appropriate according to the participants schedule;
  • Events Suggestion. When a new event is announced, the system automatically recommends the event after checking if it is interesting to the users based on their preferences. The system also checks if the weather is going to be appropriate according to the place type where the event is going to take place; and
  • Weather Service. This is a new user service. It provides information about the current weather conditions and the forecast of a location. This service is also used by the system to recommend announced travel events.

The evolution of the OLIS was accomplished by the introduction of software agents and agent roles on product line architecture.

© Copyright 2008 Ingrid Nunes. All rights reserved.