Editor's note: Inc.com columnist Alison Green answers questions about workplace and management issues--everything from how to deal with a micromanaging boss to how to talk to someone on your team about body odor.

A reader writes:

I manage a woman who is a very hard worker. She goes the extra mile, never complains, stays late, and always volunteers to help, but lately I have noticed she is getting lax on things like returning important emails in a timely manner or getting things done that I asked her to do. I know she is busy as we all are right now because we are understaffed, and all of the staff members are doing their best to fill the gaps. I also know she has some prioritizing and time management issues; she loves to do creative projects, but she takes longer on them than I would like because she wants to make them perfect.

Do I let it go, with the excuse that we are all so busy right now, or do I address it? I have been that hard worker, and I know how it feels when you are outproducing other team members and things are still slipping through the cracks. Is it fair to hold her to the higher standard that she has set for herself, even though I expect more from her than I could from other team members? She is pretty hard on herself naturally, so I want to make sure that I address this carefully.

Is it fair to hold her to a higher standard than others at her level? No. Should you be holding everyone to a high standard? Yes.

But before we go any further, I want to note that I can't actually tell from your letter what the quality of her work is like overall. You mentioned that she works hard and has a good attitude, and those things are great qualities. But they don't actually get at core performance; it's possible to work hard and have a good attitude and still not be doing a very good job. So you want to make sure that you're looking at what she gets done, not just these (certainly desirable) characteristics that she brings to the job.

As for what to do, you should acknowledge the good things that she's doing--and also make sure you're a manager who gives regular positive feedback. But you also need to be clear about your expectations and where she's falling short.

I'd have a conversation with her in which you (a) recognize the contributions she makes and the ways in which she goes above and beyond, and (b) explain that you've noticed her struggling a bit with time management and prioritization. Acknowledge that in busy, understaffed situations, it can be hard to know which things are the most important. So you want to get on the same page about how to prioritize things--and then lay out clear expectations for that. For instance, you might say that she should generally respond to emails within two business days (or less if something is important or time sensitive), that x type of requests should be handled within a day or two and y type of projects should be handled within a week, that she should proactively alert you if her workload ever means that those timeframes aren't feasible, and so forth.

Particularly in an environment that's understaffed, she may just need clearer guidance about how to prioritize things, what can be pushed back and what can't, and what to do if she doesn't have time to do everything. It may seem obvious to you how she should be juggling everything, but it might not be obvious to her. Sometimes when there's more work than time to do it all, people may respond by making choices and tradeoffs that are very different from the ones their manager wants them making--so you need to talk explicitly about prioritization and get everyone on the same page.

Speaking of expectations, you mentioned that she sometimes takes more time than you'd like with a project, but does that mean she's missing a clearly stated deadline or that she has a different idea than you do about an appropriate timeframe? If it's the latter, start setting explicit deadlines. If it's the former and she's missing clear deadlines, then part of your alignment conversation should include the need to take deadlines seriously--and if the problem continues after that, address it as a performance issue. Also, touching base on a project before its due date is a good idea, so that you can check for alignment before the problem occurs.

All that said, there's an important question your letter raises: Is this really a higher standard than you're holding other staff members to? If you're not expecting other staff members to be responsive and on top of their work, it's not fair to hold her accountable. Responding to emails in a timely way, not letting projects slip through the cracks, and making good use of time are things you need to expect from everyone. If you aren't holding others to that standard, it could explain why someone with a good attitude is becoming lax--she may be getting the wrong signals about expectations and accountability. So be sure you're addressing this angle, too.

Want to submit a question of your own? Send it to alison@askamanager.org.