Behind the success or failure of any organization, there is only one factor and that is the employees of that organization. If they work with their full efforts, then the organization is going to rise. Finding out the best employees is a very tough task. We cannot say that which method is good, but it depends on the circumstances. If an organization is having a good employee base, then it can choose an employee for the vacant position from within the organization however, if no employee suits best on that position then it can employ external sources of supplying personnel.