A very wise person once told me that "A mother is only as happy as her saddest child."

If I were to apply this sentiment to the workplace, I would say that "A manager is only as successful as their most challenged employee."

A surefire way to identify the best managers in an organization is by taking a look at how well their employees are performing in their jobs.

Yes, you can judge the quality of a managers' leadership and management style by how successful and engaged all of their employees are at work.

As a supervisor, you want to hire the best. You spend the time and energy interviewing potential candidates, carefully checking references and hiring, only to fall short when your employee is on board. Even the best, brightest, and most experienced employee cannot succeed without your clear guidance, support, and leadership. This is particularly true of new employees who are learning the culture and politics of an organization.

The best managers take pride in ensuring that their new staff are appropriately oriented to the workplace and office culture. Successful managers make sure that all of their employees have the workplace tools that they need to perform the job that is expected of them. Top supervisors insist on providing support and mentorship so that their staff can excel. Most importantly, a true leader clearly communicates their expectations to their employees instead of expecting their employees to be mind readers. These managers recognize that their success, and the company's success is intertwined with how well their employees perform at work.

So, if you are frustrated as a manager because you have an employee who isn't performing in their job at the level that you expected, take a look in the mirror. Then, take a step back, analyze all aspects of the situation, and make sure that you have done everything that you can as a leader to ensure that they have the tools, support, and commitment from you to be successful.