The engineering modification is also the contract modification, which means that some modification, superaddition or canceling is done in content of contract.

工程变更也就是合同变更，是指对合同中的工作内容作出修改，或者追加或取消某一项工作。

The tool includes five modules: data access module, metadata management module, data superaddition module, task management module and data transform, loadable module.

该工具包括五大模块：元数据管理模块、任务管理模块、数据访问模块、数据追加模块和数据转换加载模块。