Aluminium smelter operations are multifarious and someone cannot decipher various phenomenon without complete smelter knowledge. The point is best illustrated by examples. A colleague always stated, “unless you increase the voltages of some older cells, the cell does not produce to its full potential”. All the operators knew the phenomenon and acted accordingly, without knowing why? When I was transferred to Cathode Construction and did my first cell autopsy, I learnt the cause of the high voltage requirement and fixing the problem after that was simple.One of the Potline Fume Treatment Plant (FTP) had a low gas cleaning efficency. Everybody attributed it to the reuse of filter bags from another FTP. When I was transferred to the area I found the cause of the poor gas cleaning efficiency and instructed operation staff to take corrective action. The Potroom engineers were informed and monitor the alu fluoride addition and correct as necessary. Unfortunately, they ignored the warning to their own peril.I was at the receiving end in one instance. All the anode process and quality parameters were excellent. In spite of this, the carbon consumption increased. The Potroom parameters were within the prescribed norms and there was no clue. None of the efforts yielded any positive results. the discussion with Potroom staff also did not yield any clue. Then, by chance, I viewed the anode cover quality and realised that it was changed. It was confirmed by the Potroom Engineers and they had not informed Carbon Plant staff about the change and was the cause of higher carbon consumption.I regularly monitored the quality of returning anode butts and based on the observations, I had informed the Potroom Engineers of change in the cell metal curvature. They did check it and confirmed my observations. So, I rightly had a pride in my observation power, but the change in anode cover quality had gone unnoticed.