The evaluate methods of safe investment economy benefit for coal mine are classified. The Net Present Worth ( NPW) method, the Annual method and the Internal Rate of Return ( IRR) method of the economic benefit evaluation are introduced. 对安全投资经济效益评价方法进行了分类,并对经济效益评价的现值法、年值法和内部报酬率法进行了分析;
Analyzed and corrected the project's progress and investment by utilizing net worth method; 利用了挣值法对项目进度及投资等进行了偏差分析及纠偏;