巨项目系统属于复杂系统的范畴，过度复杂的系统构成增加了巨项目管理的难度。提出有效大系统，目的在于通过对巨项目系统规模、范围、要素的确定与精简，实现巨项目管理效率的提高与目标的达成。本文首先界定了有效大系统的定义及其有效性来源，然后利用模糊关系矩阵模型提出了该系统内要素贡献度与关联度的判断方法，最后采用合作博弈的优超模型解决要素间的协调问题。

Mega project belongs to complex systems category and its overly complex system structure results in more management difficult. In order to improve management efficiency and complete project target, it is proposed to use new concept to identify and streamline size, scope and elements of mega project system, which is called effective large-scale system. Firstly, the concept of large-scale system and its effectiveness sources are defined. And then, the elements’ contribution degree and correlation degree criteria are presented. The contribution and correlation degree are based on fuzzy relationship matrix. Finally, coordination problems between the elements are solved by domination cooperative game model.