In the pipeline

Origin

The phrase "in the pipeline" stems directly from the literal network of pipes used to transport resources like oil, gas, or water from one location to another. These physical pipelines represented a continuous flow and a clear path from origin to destination. As the industrial revolution progressed and large-scale infrastructure became common, the phrase smoothly transitioned into a powerful metaphor. By the early 20th century, it was being used to describe anything that was actively being processed or developed, following a set course towards its eventual delivery or completion, much like crude oil moving inexorably towards a refinery.