Along with the application of computer technology deeply into all kinds of realm increasingly, the design departments of the engineering design units and enterprises accumulated a lot of drawings and documents which existing in electronic form.

• 随着计算机技术的应用不断深入到人们工作中的方方面面，工程设计单位或企业设计部门逐渐积累起了数量庞大的以电子形式存在的图纸和文档。