How long should a person stay in same company?

  Stability professional pays the employee to stay in the company as long as the company continues to work non-stop and as long as the employee has been asked to leave Add to that stay in one company a long time gives you a great experience in the field of this company and allows you to identify all the mysteries of this area, which gives preference in this area

As long as one enjoys what he does & at the same time the company recgonises his efforts, contribution & rewards him suitably & continues doing so.

It depends on satisfaction with the organzation. If anyone joins a company or organization, my professinoal suggestion at least03 years need to prove hir or herself in any organization.

A person should stay in a company as long as there is a Win-Win situation, namely as long as he/she feels motivated and the company offers incentives and career perspectives. Otherwise it may be the correct time to search for another job as motivation will start do decline and that will affect productivity sooner or later

To be frank till he get next job with more salary & responsibilites 

As long as one is appreciated, motivated, challenged and sees learnings and opportunities that would aid him in terms of his career growth/goals. I would also like to add, in terms of compensation, one should be paid fairly.

Incase your company using the methodology of continues improving your Tools, Experience & Attitude with chance of clear career path then you shall follow them with strong buy-in.