When is the last time you conducted a cost-benefit analysis on maintenance work, and why should you do it? The answer to the second part of that question is you have limited maintenance resources. You can’t do everything so you must decide what to do. And what not to do.
You need to spend those resources on preventing the highest-cost or most critical downtime first, then use what’s left over on the lower-cost and non-critical issues. Spending two hours a day on some minor