In my point of view, no matter in any field, periodical revitalization of leadership is necessary for every enterprise, especially when it comes into trouble. However, the length of tenure varies in different fields.
 
For the first reason, not every leadership is omnipotent and omniscient. Surrounding by the fast-changing peripheral environment, they have to revise their management prudently from time to time. This spirit of self-overhauling is so in need to redeem the mistakes and avoid coming dangers timely. In 2008, because of their inadvertence of the fallible design in subprime loan, the Bush government failed to forebode the financial crisis.
 
However, although it is necessary to recheck periodically, it is hard for old leadership to do so. Because their ossified mind, leaders often fail to realize the impending danger. A best example to illustrate this is Motorola. It used to be the best-known vanguard telecom company, by developing the first beeper, mobile phone, and clamshell cell phone. However, paying too much attention on technology kills the company. Three generations of Motor's family leadership has cultivated an atmosphere of tech-awning, resulting to neglecting of the marketing-oriented trend in 21st Century. In 1990s, without an overall clear understanding on the marketing demand, Motorola mistakenly missed the opportunity to develop GSM, a new communicating system. It's marketing share slipped from 70% to 25% in 2005.
Secondly, even if they are wary enough to overhaul the leadership on time, it is hard to conduct a reform or amendment, balked by nepotism, cronyism or embarrassment on conceding his or her mistakes. For instance, Firing an ineptitude subordinate who is faithful, or rather more a relative usually seems inclement to a leader and therefore he or she would give the subordinate another chance. However, to a new leader who is not hampered by the relationships, changing a new canny subordinate. The latter way is proved to be more efficient. Success of U.S.’s governing substantiates it. A systemized stepping down of the president has effectively assured only those who is mostly sincere and mostly capable to lead American people can be inaugurated. For instance, seeing George Bush and his coterie being boggled in the quagmire for so many years, the U.S people superseded him with Obama, who rebuilt a wholly new management group and finally retracted soldiers from Iraq War.
 
But is revitalization of leadership the surest path to success? Many would argue that employee's expertise, their enthusiasm, as well as ambience of the company may also play vital roles. For instance, the ambience of inactive and indolent can destroy a company. No matter how potent a leader is, he can not do all the jobs personally. However, if the leader can instinct his or her employee’s passion, no matter through his personable and amiable charisma, or by enhancing bonus, the company might be saved.
 
Therefore, my opinion is that, all the factors influencing an enterprise are determined by leadership. A wise leader pays highly attention on enacting strategies and institutionalizing everything. The former ensures a right direction on the company, including establishment of culture ambience, product strategy for the next decades and so on. The latter helps the enterprise to run well in every aspects, from staff training and motivation, to brand building.
 
Finally, five years should not be a stipulation for the tenure. Since a revitalization of leadership inevitably brings into disfavoring byproducts, such as friction between new leadership and original inner environment etc., how frequent the revitalization should be depends on the enterprise’s forbearance on these cost. However, this varies in different fields. In the field of education, as the environment is more stable, the tenure of a leader could be longer.