How to apply Ziegler Nichols and Cohen and coon tuning?

http://i39.tinypic.com/332p8wh.png The problem given to me is as above mentioned. For above system when I follow Ziegler Tuning, I get oscillations at ku= 3.105 and pu=1.8sec. Now when I compute and substitute the values I am not getting the accurate result. Please help me as how to perform the Ziegler Nichols and Cohen and Coon method for the problem. Provide me with step by step procedures. Thanks, BHARATH

[JANANI]

Please mention the system function properly

Answer 1

[Arkadiy Turevskiy]

Take a look here , specifically under "classical design formulas".