30 Percent of Employees Feel Indispensable. That's a Bad Thing. When you bring in automation, tell employees that just because they're no longer indispensable doesn't mean they're not still valued.

Working vacation is an oxymoron that has become so popular, it's now the norm. An April 2017 Glassdoor survey of 2,224 Americans found that 66 percent of them worked while on vacation. Of those, 30 percent said the reason was that there was no one else at their company who could take over their responsibilities.

Related: Why You Really Need to Unplug While on Vacation (Infographic)

On the surface, the fact that employees like those surveyed felt indispensable seems like a good thing. But, in reality, being the only one who can shoulder a burden creates a lot of stress. And when these employees burn out and leave for good, the company suffers.

Instead of letting your employees feel indispensable, focus on keeping everyone happy. Show them it's all right to take time to recharge. Here's how:

Respect business hours.

Disconnecting from work outside of the office needs to be a habit -- not just something leaders allow employees to do when they go on vacation. It's better to set a daily precedent where work is done only during work hours.

This is why New York-based business intelligence software company Sisense created its "Coming Up for Air" program. Once a quarter, the company schedules a long weekend and requires that all employees disconnect out of the office. No phone calls or emails between team members are permitted.

This time off helped at least one employee in an unexpected way, according to CEO Amir Orad. The employee had a constant need to feel productive, but on one long weekend, she disengaged and took her daughter along with her to perform a simple errand.

"It was a trip to the doctor, not to Disneyland," Orad explained in an email. "But, surprisingly, she discovered she had some fun with her kid, which was kind of unexpected, but also the whole point of disengaging from work."

Related: The Secret to Increased Productivity: Taking Time Off

To help employees understand the benefits of time out of the office, have them share their activities when they come back to work. After a long week or holiday, have employees write down what they did and why they enjoyed their time off. Then, hang these notes up in the office as a reminder that employees can relax without worrying about the company crumbling.

Automate when possible.

While it's always nice to have a human touch, some aspects of work are better suited for automation. Employees might be reluctant to hand over certain tasks to the latest tech tool, but that action can take away unnecessary stress in the long run.

For instance, Bellevue, Wash.-based intelligent process automation platform Nintex formerly required the company's receptionist to handle a lot of day-to-day tasks. She checked in visitors, validated parking and was the general information hub of the office. But all these responsibilities made her feel tethered to her desk. After some of these tasks were automated, she found she had more freedom and less stress.

"There's a difference between being valuable and being indispensable," Kim Albrecht, vice president of corporate marketing, said in an email, recounting this anecdote. "'Indispensable' leaves a person and a company vulnerable because there's little-to-no backup or support."

When introducing automated technology, explain to your employees that these systems are there to support, not replace, them. Explain, too, that these tools are there to relieve stress. This will help them see that just because they're no longer indispensable doesn't mean they're not still valued.

Focus on succession planning.

When your startup is small, you may find it difficult to build in productivity safety nets. Because employees already have so much on their plates, it doesn't seem practical to cross-train them for other roles. But it may mean that when a key member of the team is out of the office, no one is there to pick up the slack.

William Vanderbloemen, founder and CEO of the Houston-based church staffing company Vanderbloemen Search Group, told me he learned this lesson the hard way.

"When I first started this company with my wife, she had a rule that I couldn't go skiing for the first year that we started the business," he said via email. The reason? "If I broke my leg, I couldn't get on a plane," Vanderbloemen continued. "If I couldn't get on a plane, I couldn't meet with clients. If I couldn't meet with clients, my family couldn't eat."

Once his company became larger and more stable, Vanderbloemen made succession planning a priority. For every key role in the company, he said, there is someone currently in a junior role who is learning the ropes. This way, when someone is out of the office, the junior employee can step in and gain experience at the same time.

Related: 5 Ways to Persuade Employees to Take Vacation Before They Burn out

So, do the same thing: Build succession into employee training. Meet with employees and find out how they want to move up in the company. Then, partner each of them with a senior employee and schedule a day each month to shadow that senior employee, to learn and (safely) make mistakes. That way, when it's time for the "student" to step up, he or she is ready.