This is the distillation of many thousands of man-years of human effort. 这是要用好几千个工作年计算的人类劳动的结晶。
The decision to start over from scratch is basically a decision to throw away many man-years of effort and lessons learned that the current system implementation encompasses. 从头开始基本上是一个丢弃现有系统执行过程中获得的众人多年努力和教训的决定。