What is the major difference between an old lame experienced employee & a energetic, smart, quick learner employee.?

Both have their own advantages and disadvantages for an established company. However, the major difference lies in the use of state of the art technology for enhancement of productivity and improvement of quality of products or services. For example in Japan old employees are considered as an asset of the company who know everything in the company are they are rotated in different jobs of the company. This gives them advantage in finding solutions which are not expected from an inexperienced person, wheres promptness, long hour or stressed job are expected from young and energetic employees.