工期与成本作为工程项目目标控制的主要方面，是工程项目在各阶段的主要工作内容，也是工程建设各方主体的中心任务。两者之间相互影响、相互作用，是辩证统一的。在工程项目实施中的工期控制与成本控制，就是为了达到预先设定的项目目标和理想的控制状态。本文从工期与成本两个目标存在的问题、影响因素、基本原理和方法、采取的对策与建议等方面进行了探讨与分析，进而研究工期与成本之间相互作用和控制协调的机理。具体内容有以下几个方面： ⑴讨论了控制论的基本原理与方法，以控制论的基本原理和思想为基础，探讨分析工程项目工期与成本控制的原理、内容、过程以及控制方法，总结应采取的相应措施。 ⑵为了全面了解工程项目管理的发展现状，更好地实现工程项目工期与成本控制，本文采用《工程项目管理专家调查表》的方式采集了陕西省范围内建筑行业大量专家的意见，并进行详细的归纳分析，得出较多有参考价值的结论。 ⑶为了能定量指导工程建设的实施，掌握具体的作为控制、评价工程项目工期与成本的参考标准或数量标准，本文采用《建设项目调查表》的方式掌握了第一手的数据资料。经过对大量数据的分析整理，研究西安市范围内几类不同使用功能、结构形式建设项目的工期与成本控制指标值。 ⑷研究工程项目工期与成本之间的相互影响关系、控制协调机理。基于协同学的相关理论，提出了资源与天气因素影响下的工期与成本优化控制模型；探讨分析工程项目组织协调的意义、内容、协调技术与方法等。

As the major aspects of engineering project targets control, schedule and cost are very important content on each progress of project, also are the core tasks of each unit in the project construction. The two aspects which has effect on each other are united. The purpose of carrying out schedule and cost control of the project is aim to the project’s destination beforehand and the best control level. Based on studying the two targets’ defects, effect factors, basic principle and methods, countermeasures and advice which should be taken, the paper discusses and analyses these content: 1.Based on the basic principle and thinking of cybernetics, this paper discusses the basic principle and methods, at the same time analyses the principle, content, progress and methods of schedule control of engineering project management, also summarize the corresponding actions that should be taken. 2.In order to know about developing conditions all-around of engineering project management and achieve to control schedule and cost more effectively, the paper has collected many experts’ advice in Shaan’xi province by using construction project questionnaire. Thereby the paper draws some useful conclusions through summarizes in particularly. 3.In order to quantitatively conduct the application of engineering construction and generally master relevant reference or quantity criterion that could evaluate schedule and cost of engineering project, this paper has grasped the first-hand datum by using construction project questionnaire. Via a lot of work on the large datum, this paper studies schedule and cost’s control index values of engineering project by way of different functions and structure types in Xi’an. 4.The paper studies relationships that affect each other and control coordination mechanism of engineering project. Based on relevant theory of Synergetics, this paper raises optimum control model on influencing of resource and climate. The paper discusses and analyses significance, content, coordination techniques and methods etc. of engineering project organizing coordination.