This paper presents the effect of various control tuning methods to the controllability of air temperature oven system. The simplest open loop test on actual plant has been performed using a Reformulated Tangent Method (RTM). Three PID tuning rules namely Ziegler Nichols (Z-N), Cohen Coon (C-C), and Chien, Hrones & Reswick (CHR) are used in this work. The plant is connected to Distributed Control System (DCS). The performance of these control tuning rules are evaluated in term of their closed loop characteristics such as percent overshoot (% OS), settling time (Ts), rise time (Tr) and integral absolute error (IAE). The results of this study showed that Cohen-Coon tuning method give best performance to the controllability of air temperature oven system as compared to the other rules.