A Saudi Aramco Refinery operates a Two-Stage Hydrocracking Unit with a “Debutanizer First” Fractionation Scheme. The plant configuration is such that the performance of the debutanizer column has an impact both in terms of light ends recovery and more critically the H2S related corrosion issues both in the low pressure and high pressure loop within the unit. This paper analyses the process performance degradation of the Debutanizer Column by trying to understand and identify the primary causes of the problem analyzing the same and coming up with a possible solution. An integrity assessment was carried out to down stream equipment of the debutanizer heater reboiler fractionator and transfer lines to study the effect of unexpected H2S slippage. Severe high temperature H2S corrosion (sulfidation) and wet H2S cracking was observed. Corrosion loops and Risk Based Inspection (RBI) were used in this assessment to determine the future inspection and operational strategy. This paper also deals with how simulations and predictive analytic tools have been successfully used in providing short-term mitigation control; the flagging of the leading indicators a development of a dashboard for the operating staff and the recommendation for the revision to the multivariable control system (MVC) and long-term engineering solutions; ability to change the stripping efficiency without change in the yield pattern and the reduction in the overall H2S content in the loop thus reducing both the corrosion and fouling rates.(Saudi Aramco PRD tracking number 13-2498)