Most senior managers have no idea who the company's most valuable employees are. Here's how to pinpoint them before they burn out and quit.

• Effective people management is about being able to identify your most influential employees.
• Otherwise, they might get overwhelmed by requests for help and quit.
• It's especially important to know who your company's influencers are in today's collaborative workplace.
• Visit Business Insider's homepage for more stories.

Ask a C-suite executive: "Who are the most influential people at your company?"

They'll probably get it wrong.

Chances are, that exec will pinpoint coworkers at the top of the food chain. But at many companies, the most influential employees - the folks everyone turns to with questions and relies on to get their work done - aren't senior managers. They're middle managers, or maybe individual contributors, embedded deep within the organization.

In other words, these linchpin employees don't necessarily wear suits and talk about business strategy at conferences. Instead, they're in the field, translating that vision into reality on a day-to-day basis.

And senior management's oblivion to how valuable these people really are can pose a major threat to the organization. If influencers don't get the support and resources they need, they might get overwhelmed by all those requests for help, then burn out and quit.

It's a pattern Kevin Oakes has seen often as CEO of the Institute for Corporate Productivity (i4cp), a research firm whose partners include Microsoft, Amazon, and Citi, especially given the recent increase in collaborative work environments.

Oakes presented i4cp research at LinkedIn's annual Talent Connect conference, which took place this September in Dallas, to show why leaders need to enlist their "invisible" influencers in the process of changing their company culture. Yet even for companies who aren't prioritizing culture change at the moment, it's important to know who those key influencers are.

Once an influential employee, or a "hidden star," is gone, Oakes told Business Insider, "a lot of times that network structure implodes upon itself because you were so dependent on that individual."

Influential employees are often bombarded by requests from coworkers across the company

This problem isn't exactly new, but it's more relevant now than ever.

Research led by Rob Cross, professor of global business at Babson College, has found a meaningful increase in workplace collaboration, due in part to people bombarding each other with messages on email and Slack.

But the trend is also attributable to a move toward matrix-based management and dual-reporting systems, which is a fancy way of saying that employees receive assignments from more than one manager.

The first step to reducing the chance of collaborative overload is to pinpoint the key influencers in your organization. To that end, management experts recommend doing an "organizational network analysis" (ONA).

ONA can take many forms. HR might simply ask employees to fill out a survey on how they get work done - though there's always the risk that people will misrepresent or misremember their actual experience.

Another option is to monitor activity on tools like email or Slack to see who's chatting most often with coworkers in other departments. "You can pick up on where the center of the beehive is," Oakes said.

Influencers can reduce their own workload by setting boundaries on their helping behavior

The goal here isn't just to reward those influencers with a raise or a promotion - though that probably wouldn't hurt. It's also about recognizing how much they're juggling, and keeping tabs on their workload. Often these people "have too much on their plate and they're too much of a resource for people," Oakes said.

On his website, Cross shares questions that managers might ask themselves once they identify influential employees. For example: Is this person a "flight risk" because they may feel overloaded? Does this person need a team because "her capabilities could be scaled exponentially with the right talent around her?"

But employees who feel overwhelmed (even if they're not sure they qualify as a key influencer) don't need to wait for a manager to intervene.

Take it from Adam Grant, a Wharton professor whose 2013 book "Give and Take" made a compelling case for why people who are willing to help others ("givers") are most successful professionally. Grant also warns against giving inefficiently, which can lead to burnout if you don't see the impact of your contributions.

One strategy Grant recommends for giving efficiently is "chunking" your favors. Instead of helping people on an ad hoc basis, you might hold office hours or just let your coworkers know that you'll be unavailable for a certain portion of the day. Another Grant-approved strategy is doubling down on the activities that allow you to make the greatest difference, and letting go of the others.

Then again, sometimes it does take a manager, or an outside observer, to clearly see an employee's value to their company. Based on his research, Oakes said the most influential people in an organization don't always think of themselves that way.

"Sometimes they're operating in a little bit of a vacuum," he said, "not recognizing just how much they're contributing to the company until somebody recognizes them for that."