In general, we will create a system to deal with what a problem occurred, then do it in practical and do some checking and supervising operations.

Today I will give anot

her mind on this issue, suppose the regular is not available for the problem, the pepole who executes the regular in disabled, the checking and supervising operations are not executed, for those reasons, the regular will be failed, think it in con, why the problem will occur? who operate the problem? the problem occured occasionally or continually?  if the problem did not occur, so nothing need to do, along this mind, if some problems occurred, the first thing, we should think how to prevent it occurring, the second thing is that creates a regular to deal with it.