Why some chemical plants never stop, and others never run non-stop. Two entirely different ways of turning raw material into product — and a real engineering tradeoff, not a case of one being the "upgraded" version of the other.
Walk into a large petrochemical complex and the process rarely stops — feedstock flows in one end, product flows out the other, around the clock, for weeks or months between planned shutdowns. Walk into a pharmaceutical manufacturing suite and you'll find the opposite: a defined quantity of material loaded into a vessel, carried through a fixed sequence of steps, and completely discharged before the next batch ever begins. Neither plant is doing it wrong. They're solving different problems, and the processing mode follows from the problem — not the other way around.