中文摘要：

CAD和CAPP系统的集成一直是一个研究中的难题，其原因在于由于信息表达的不一致，使CAPP系统需要针对不同的CAD系统设计专门的信息提取模块，而对于CAPP下游来说，CAM也不能利用全部的产品设计和工艺信息。STEP标准作为CAD系统的输出，可以为OAPP系统提取信息提供一个统一的接口。而STEP—NC作为新一代数控标准，继承了STEP标准的属性，可以作为CAD／CAPP／CAM／CNC集成的桥梁。应用STEP中性文件，CAPP提取产品的制造特征和加工工步，生成工艺文件，并以STEP—NC中性文件形式输出，便于后续CAM和CNC系统的调用，从而达到CAD／CAPP／CAM／CNC信息集成的目的。

英文摘要：

For a long period, the integration of CAD and CAPP is a problem bothered people. The reason lies in the disagreement of their information. CAPP system must design a special model to pick-up information from every different CAD system. At the same time, CAM system can＇t use all of the product＇s design data created by CAD system and the process information developed by CAPP system. As the export of CAD systems, STEP can provide the uniform interface to CAPP system. STEP-NC is the new generation numerical control standard, which inherits the STEP standard. It can become the bridge for the integration of CAD/CAPP/CAM/CNC. After acquiring information from STEP file directly, by finding the machine features and their workingsteps, CAPP system can generate process plans and output a STEP-NC file which can be applied by CAM and CNC system to approach the integration of CAD/CAPP/CAM/CNC.