In today’s highly competitive job market, the option to re-hire a former employee could prove invaluable to many small businesses.

Hiring a typical job-seeker–that is, someone completely new to your organization–is fraught with all the expected risks. Does he or she really have the skills to do the job? How well will they fit in with their co-workers and our culture? What if we’ve made a huge hiring mistake?

On the other hand, recruiting and re-hiring an ex-employee (or what’s become known as a “boomerang employee”) may eliminate some of these nagging questions. Of course, since no hiring outcome can be absolutely guaranteed, there are additional risks to consider.

Here’s a look at the pros and cons of the decision to re-hire a former employee:

You know what you’re getting.

Generally speaking, you can rely upon your knowledge and experience of a former employee when considering whether or not to re-hire them. In many cases, you can access the individual’s prior HR record and take a close look at his or her performance evaluations during their time of service. As a result, there’s often less risk when contemplating a re-hire move.

The boomerang employee knows your business.

An ex-employee is already familiar with your culture, products, customer service strategies, internal processes, and so on. This can sharply reduce the need for training (and the costs/time involved).

They bring a fresh outlook.

Let’s say the employee originally left for a “better” opportunity. Employees who wish to return, notes Forbes, might have “gained valuable experience during the time they were gone,” perhaps a “new skill set, more leadership experience, or even experience and insights into how other companies handle situations” that can be of value in your workplace.

The returning employee can motivate your current staff.

At one time or another, all employees wonder if the grass is greener somewhere else. The presence of a re-hired boomerang employee “can improve department retention efforts by attesting to improvements made since they left,” according to Glassdoor.

With these positive elements in mind, you should also consider the impact of some potentially negative factors:

They were let go for compelling reasons.

A former employee who you terminated for poor performance or inappropriate behavior is obviously a bad candidate for re-hiring. As Insperity notes, “the underlying behavior behind performance problems and personnel issues … is not easily changed.” A person who “was a problem employee before will probably be a problem again.”

They harbor lingering resentments.

Sometimes, a departing employee feels mistreated or otherwise slighted in some way. It’s vitally important that no such lingering grudge is still present; otherwise, the personality fit won’t work.

Coincidentally, rehiring an ex-employee might trigger anger among your current workforce, and prompt other staff defections.

They cling to old habits.

A former employee who seems stuck in “old” ways of doing things might not meld nicely with your new, improved company culture. If you cling to “how I did things in the past”, you can do a disservice to your operational processes now.

So how can you go about determining if the “pros” outweigh the “cons” of rehiring?

Ask tough questions.

Be sure you interview an ex-employee just as you would any other job candidate (same questions, same scenarios, etc.). But go further. Ask open-ended questions designed to uncover what types of knowledge and experience they’ve acquired since leaving your company. Also, ask questions that help you better understand their feelings towards your business, both in the days of their exit and now. You may or may not get sincere answers, but reading between the lines may help clarify the situation.

Talk with other team members.

Depending on the circumstances, there may be several current employees who remember the person now being considered for re-hire. Talk to your HR staff about the best way to approach these employees, with the goal of discussing the impact (favorable or otherwise) of bringing the ex-employee back on board. If you encounter great enthusiasm among staff members, the decision might become clearer. But if the former employee’s return generates considerable resistance, it’s a red flag you should seriously consider.

In past job markets awash in candidates, there were always new people to contemplate hiring. When qualified job candidate selection is more limited, the idea of hiring a boomerang employee can make a great deal of sense. Explore various opportunities and then use your best judgment about that final hiring decision.