The maintenance of petroleum product quality is one of the many challenging tasks in refinery processes. The petroleum refining processes transform crude oil into useful products such as liquefied petroleum gas (LPG), petrol, fuel oils, jet fuels, etc. This topic will discuss various challenging issues, giveaways, and violations that affect the quality of petroleum products. It considers different methods to minimize or eliminate giveaways and violations to maintain the quality of petroleum products. There is a discussion about the required features of the distributed control system (DCS) of a regulatory blend control.