翻译 长弓 1995-09-29 Once a program is completed,maintenance begins.Since it is impossible to test many large programs exhaustively,bugs can slip through the debug stage, only to show up months and even years later.Fixing such bugs is an important maitenance task.More significant is the need to update a program to keep it current;for example,because income tax rates change frequently,a payrool program must be constantly updated.The keys to maintenance are careful planning,good documentation and good program design. 维护 程序一旦调好，维护就开始了。由于不可能彻底地测试许多大程序，在调试阶段中，一引起错误可能溜过去，几个月甚至几年以后才暴露出现。找出这些错误是非常重要的维护任务。更主要的是需要修改程序以使其可继续使用。例如，由于所得税率经常变化，必须经常修改工资程序。维护的关键在于仔细地规划、完整的文件编制和令人满意的程序设计。