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.

Here's a roundup of answers to four questions from readers.

1. My employee messed up an important project

I manage a team of six in a small STEM firm. My employees are, by and large, fantastic. They do their work on time, at a high level, with great attitudes.

Recently, one of my employees didn't complete a project on time. He promised the work on Tuesday, which then went to Thursday, which became Friday, then Monday. When I told him we absolutely needed it by the next day (Tuesday), he complained that I had never told him this was a high priority ... and if he had known, of course he would have had it done on time! But I did tell him that, every time we discussed this.

His work on other projects is great, so I have no interest in firing him or anything like that. My company is small, so we don't have things like formal improvement plans or anything like that. What tools can I use to make sure this kind of thing doesn't happen again? Should he be disciplined somehow--and if so, how? Or trained? I don't have to give that much criticism or discipline in this job, so I'm a bit at a loss now.

Green responds:

When a good employee messes up once, don't start thinking about formal improvement plans or discipline. Just talk to the person about what happened and why! In this case, sit down with your employee and say, "Let's talk about what happened with the X project. It was due on the 10th and I didn't get it from you until a week later. You mentioned that you didn't know it was a high priority, but I literally said the words 'high priority' every time we talked about it. I want to make sure this doesn't happen again, so let's figure out where we miscommunicated. What's your sense of what happened?"

This should be an genuine discussion, where you're sincerely interested in his feedback. Since he's an otherwise good employee, it's possible something is going on that you didn't realize (including that you might not have been as clear as you think you were). See what he says, and talk it through. If it turns out that he just didn't take you seriously, then say, "Going forward, let's agree that if I say something is high priority, I need you to tell me in advance if you think you won't be able to make that deadline so we can figure out how to handle it, not wait until it's already overdue."

The main benefit to this conversation is that you'll both come out of it with a better understanding of what happened and what should happen differently in the future. But it also creates accountability: You're demonstrating that if people let things drop like this, there's going to be a fairly serious conversation about it, and that reinforces how you expect people to operate. (If your employee had a pattern of messing up, this would be a different conversation -- more about the pattern and that it's a serious concern. But that's not the case here.)

2. My employee quit smoking and has become cranky at work

I have an employee, "Joy," who is a lifelong smoker. Joy is a member of my leadership team, and has been a great asset for the three years I've worked with her. Recently, she decided to quit smoking. I'm really proud of her, and she's been doing an awesome job at sticking with it.

However, since she quit smoking, I have noticed a sharp dip in her performance and attitude. Joy admits that this is because she is severely craving a cigarette, which has always been her main form of stress relief. While I sympathize, and am still proud of her for taking this step toward bettering her health, I am getting frustrated. The team has noticed her change in attitude and are getting frustrated as well. How can I approach this as her manager, while still remaining supportive?

Green responds:

How cranky is she being? If she's just a little cranky, cut her some slack -- everyone goes through things in their personal lives that impact their demeanor at work now and then. But if it's extreme -- if she's being rude or hostile to people -- then articulate that for her and tell her she needs to rein it in. For example: "I know this is a tough period for you and I sympathize, but you're starting to be openly rude to people here and I need you to stay civil."

Same thing with performance -- if she's slipping a little but is still doing an overall OK job, cut her some slack since you know what's causing it and you know this is short-term. But if it's more serious, then you need to say, "I know this is a tough period for you and I don't expect you to be at 100 percent right now, but you're making some pretty serious mistakes in your work. What can we do during this period to help keep your work quality where we need it?" And since she's normally a good employee, you should also try to find ways to accommodate her for the next few weeks, like moving deadlines around if you can or giving her projects that require less mental presence if that's possible.

3. An obviously pregnant colleague who hasn't announced her pregnancy yet

My question is about a colleague who we're sure is pregnant. There are only three of us in our building and we are pretty close (both as work friends and literally; we see each other all day and share a bathroom). Our colleague has given up caffeine and has been nauseated for the past two weeks, so we're betting she's not far along, but we obviously don't want to put her on the spot about her private life.

Since she is rushing to the bathroom to be sick every day, how can we be tactful without revealing that we know what's up? It seems so rude to just ignore that she's not feeling well!

She mentioned that she gave up the coffee because it's bothering her stomach, but that's as much explanation as she's given. She's just quietly sipping on ginger ale and eating saltines all day. I guess we just follow her lead and say, "Gosh, sorry you're feeling queasy"? We're also planning a work trip in a few weeks for which she and I have booked a shared hotel room as we normally do, but now I wish I could give her an out so she can have her own space.

Green responds:

Yep, follow her lead, even if it's really obvious to you what's going on. In fact, I'd think about how you'd act if you were somehow sure she wasn't pregnant and do that. When she's ready to talk about it, she'll tell you, but you shouldn't force her hand.

For the work trip, though, you could say something like, "I know you haven't been feeling well lately, and it can be hard to share space when you don't feel well. I always like sharing a room with you, but would you rather have your own room when we go to Boston? I'd understand if so."

4. Approaching a manager in public about a job

Let's say I visit a café close to my office every day at 3 p.m. for a cup of coffee. I also see a manager whose team has an opening, and I possess the qualifications required to join his team.

Are managers in general open to being approached by potential candidates in a public setting such as a café and having a five to 10 minute chat if they have time to spare? What if the manager works for a company that is different from the candidate's? Would they still be willing to talk to the candidate for a few minutes? They may stumble upon a very talented individual for their team.

Green responds:

Don't do it! There are some managers who are always in recruiting mode and are happy to talk to potential candidates anytime, anywhere. But there are far more managers who would be annoyed to be interrupted while they're trying to have a quick break in their day.

And it's not as if interrupting someone in public is the only way to reach them and you have no other options. If you're interested in approaching a hiring manager, you can do it over email or LinkedIn, where they can respond when it's convenient for them and where you can include a copy of your résumé, so they can figure out right from the start if it even makes sense to talk. (And if you're really just interested in applying for a specific job with them, go ahead and apply, following the application instructions, since otherwise you'll come across as if you're trying to circumvent their process.)

The one exception to this is if the person works for your company. In that case, it's reasonable to talk to them informally -- but I still wouldn't do it when they're trying to relax.

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