Some of the most successful business leaders in a company wind up becoming legends when they retire or otherwise depart from a company. Amazon's Jeff Bezos, Google's Larry Page, Facebook's Mark Zuckerberg – these are all notable business leaders who have redefined (or even invented) their industries and will leave a lasting mark on their companies. When they depart, new people must fill the void – a hard task for any person, regardless of whether they are a seasoned veteran themselves or an outsider being hired from another company.

Harvard Business Review contributors Dorothy Leonard, Walter Swap and Gavin Barton recently wrote an article about the challenges businesses could have filling the void. They build relationships that then have to be rebuilt – even if the former leader leaves all of his or her client contact information, that data is useless without the years of experience and interaction backing it up. New leaders still need to create their own name within the industry, just as their predecessors did. Finally, there is the need to help the new guy get up to speed – how can they be expected to innovate within the sector when they do not understand their companies' products and services at the same level of their predecessors?

The leadership gap
Another element not addressed in the article is that when legendary executives retire,  they also takes their years of experience of leading others with them. This is potentially the most difficult thing to replace, as enterprises often revolve around the way truly prolific leaders operate. Often times, new and younger replacements do not have as much experience dealing with people, customers and clients – some may even have no experience in these areas at all.

The leadership gap is a problem many companies are facing right now, particularly as the Baby Boomer generation retires and the millennial generation is being called up into leadership roles. With the older executives retiring, they are taking their years of leadership skills with them. Now, younger, relatively inexperienced workers are expected to pick up where older managers left off, but with a fraction of their experience when it comes to leading and influencing others.

Getting leaders up to par
While relationships cannot easily be transferred person to person, leadership is a skill that can be taught. People are not natural born leaders, it is something that is learned. However, whereas most people learn great leadership skills over time from experience, it does not have to be that way – it is a skill that can be taught as well.

Business development training is a critical tool for helping young leaders get up to speed as quickly as possible, particularly when companies have to deal with an unexpected departure or a series of retirements that really challenges their bench of leaders. Rather than putting new leaders in a sink-or-swim position, leadership training can wind up being a meaningful endeavor.