When you picture achieving success, you probably imagine a graph rising steadily to the right, with the top point of the line being somewhere around fulfillment, lots of cash and real authority in your field.

Reality check--the graph often rises to a given point, then cuts sharply to the horizontal and stays there.

It's a situation known for decades as the Peter Principle. The concept, made famous based on research from Lawrence J. Peter published in 1969, says that people rise to the level of their incompetence. You'll keep getting promoted until you simply don't have the skills or knowhow to get any further. And at that point, your career takes a seat and stagnates.

Why Stagnation Happens

Phil Shawe, CEO of TransPerfect, which provides translation/language services and related technologies, oversees a workforce of 5,000 employees in over 100 offices worldwide. He addresses the Peter Principle and other common issues as part of his Management 101 training, as he sees it most commonly when individuals first take on managerial responsibility. And he told me that part of the problem is the way that leaders and hiring managers evaluate candidates in the first place.

Those in charge of filling positions are supposed to promote or generally hire people who have the skills to complete the available jobs well. But instead, Shawe asserts, they promote based on how candidates have performed in their current role. That is, while skills necessary in your current job aren't necessarily going to translate well to a higher position, leaders often assume they will.

For example, a company might consider a salesperson for a manger job according to whether they've hit revenue targets and other quotas.

"While those are important skills to have," says Shawe, "they won't always be an indicator of, for example, the interpersonal and communication skills required to supervise others."

Pushing Past Peter

As a leader, ensuring that you don't put people in positions where they won't be successful first means switching to a more future-focused view of available jobs. Make sure that you're asking candidates to demonstrate proficiencies they'll need moving forward, rather than proficiencies that have served them well in the past. Look critically for those proficiencies on their resumes. And if you can, use hands-on trials that give candidates a chance to actually solve problems and interact with your team.

But part of great leadership is also giving the people you've hired the chance to move up the ladder. In fact, contemporary workers look to do so quite quickly, with 75 percent of Gen Z workers typically expecting a promotion in as little as a year.

So once you have someone doing well in a position, talk with them again about where they want to go and what their aspirations are. Consider what jobs are going to be upcoming that could be a good fit for those goals. While you of course want workers to stay with you, see the bigger picture of advancing and building connections within your entire industry and consider positions anywhere that could be critical for the person's career. Then work with your employee to develop the skills they're going to need to qualify for the upcoming jobs, whether that's finding them a mentor, arranging shadowing, sending them to in-house training or getting them enrolled in specific courses.

Remember through this process that the Dunning-Kruger effect is very real. This principle says that people typically are not aware that they are incompetent, simply because they need additional skills to self-assess properly. You might have to find tactful ways to help people on your team be aware of the areas where they could grow, or to convince them that the growth is necessary.

But you also should look to avoid stagnation for yourself, too. It's important not only because it helps you stay personally fulfilled, but also because your business is going to evolve and therefore require different things from you as a leader over time, even if your title doesn't change. And Shawe's recommendation here is simple.

"Always be learning. [...Studying your company and [...] concepts such as management and marketing--and advancing those studies as your job evolves--can be tremendously powerful tools to avoid career stagnation."