ceaseless checking/checking again and again

[keannu]

Source : self practice
[FONT=&#48148]As I simply described, my job is a tremendously careful work that needs ceaseless checking/checking again and again. If I missed some failure-causing points and fail to find out the cause, the failure can’t be improved and causes a great loss in mass production.[/FONT]
[FONT=&#48148] So while I’m working, I try to find out evident/apparent causes to improve the quality of products by being extremely cautious.[/FONT]

Which ones wold be more appropriate in the underlined parts?

 

[Tarheel]

Perhaps:

My job involves meticulous, careful work that requires ceaseless checking.

 

[Tarheel]

The phrase "the failure can't be improved" doesn't work.

 

[keannu]

The phrase "the failure can't be improved" doesn't work.

Maybe does the following work? Why doesn't "improve" work? If I said "overcome failure", that would be to get rid of it.
I think probably "failure" can either persist or be removed.

I can't overcome the failure/defect.

 

[Tarheel]

Perhaps:

It can't be fixed. Start over.