Exxon Mobil Corp.’s worst refining performance in almost two decades may revive questions from analysts about the so-called integrated model engineered by founder John D. Rockefeller and espoused by every CEO in the company’s 149-year history. A surprise loss in a business line Exxon typically relies on to prop up more volatile units eroded first-quarter profit and cast doubt on the strength of the oil titan’s comeback from its annus horribilis in 2018. In the last decade, when other oil companies spun off refining businesses to concentrate of drilling for crude, Exxon steadfastly adhered to the wells-to-retail model. The refining loss is particularly stinging for Exxon Chief Executive Officer Darren Woods, who rose through the ranks of the fuel-making side of the company rather than the oil-exploration business of his chief competitor for the […]