Chemists, Chemical Engineers, and Plant Managers

The framework distinguishes three kinds of work: chemists discover what works and why, often through experiments that are messy and impractical; chemical engineers turn successful discoveries into scalable systems, managing throughput, cost, variability, and interconnected processes; plant managers operate established systems reliably, focusing on quality, staffing, maintenance, and continuous improvement. ThredUp illustrates the progression: an early experiment showed that customers would send in clothing, operations teams built processes to handle the influx, and later managers kept a vast operation running as automation expanded. The author identifies himself as a chemical engineer whose career grew through designing systems and tackling increasingly broad business problems. A reorganization moved him into plant management, a role that brought a promotion but left him unhappy because it required work outside his strengths.

The framework is also a guide to leadership and organizational design. Advancement often pushes people into management roles that do not suit them, while companies can mistake a mismatch between a person and a job for a personal failing. The author recounts hiring a machine-learning researcher, a “chemist,” to improve an existing production system - a chemical-engineering task. The researcher pursued a new system rather than incremental improvements, exposing the manager’s hiring error. As companies grow, protective processes can crowd out discovery and system-building. Leaders should distinguish genuine changes in job requirements from environments that prevent capable people from succeeding, and create paths for people to advance without abandoning the work they do best.