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Sven Jacobi
Multiagent Systems Group
DFKI, Geb. 43.8
Stuhlsatzenhausweg 3
66123 Saarbrücken

E-mail: jacobi@dfki.de
          
 
  

Scheduling of independent tasks based on multiagent systems with soft constraint solving in electronic markets

Keywords: multiagent systems (MAS), Scheduling of independent tasks (SIT), constraint solving, hierarchical constraint satisfaction problems (HCSP)

Supervisor: Michael Schillo



This diploma thesis describes how to use multiagent systems efficient to solve hierarchcal constraint satisfaction problems. It is shown how you can use both research topics in an user-specified enviroment.

In most business-processes in which there are several distinct persons involved you have to deal with conflicts of goals which the different persons are trying to reach. Often, the persons even have preferences or wishes regarding their working time. These preferences might have an bad influence on the efficiency of labor, but never the less you want to take them into consideration unless you satisfy all your goals you´re trying to reach. Therefore it is useful to develop a system which keeps all the goals and satisfies nearly all wishes of the persons who are working on the same task.

In this thesis we have developed such a system which works as follows. A disponent gets orders from the electroic market realized as an agent platform. For each order he starts a contract net protocol with the workers which are also represented as agents on this platform and are able to satisfy the demanded order. Each worker can formulate his wishes and preferences regarding his working hours in a calendar distinguishing even certain strengths among these wishes. During the protocol the system generates hard constraints and soft constraints out of this calendar and uses Cassowary to solve the constraint hierarchy which is constructed as described. So each worker-agent sends his proposal to the disponent who has to decide how to realize the order. Therefore he tries to satisfy all preferences of the workers since they don´t contradict the accomplishment of the whole order.

For each order the system recognizes the workers wich are able to fulfill this order. So each disponent-agent is able to communicate with an always changing number and type of worker and vice versa each worker can be contacted by several disponents.

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