Abstract: The interactions between the task process and members'behavior take place through the match of members'ability and demands required by tasks and the enhancement of one's ability through learning in task process. To address how the interaction affects team effectiveness,a multi-agent model is put forward based on casual analyses of various factors involved in team's task process. The model is implemented into Member-task Interaction based on Team Effectiveness Simulation System by Repast. J 3. 1. Experimental scenarios are designed and simulated to verify and validate the system. Then,we use the system to explore the effect of task size and fluctuation magnitude of member relations on team effectiveness and task allocation. The results show degree of that team's member relationship and task cost can not achieve optimal values simultaneously,and suggestions are provided on how to enhance team effectiveness.

Key words: team effectiveness, member-task interaction, multi-agent simulation, repast