Final answer:
W. Edwards Deming was not making a professional impact during the Scientific Management Era; this was the era of Frederick W. Taylor and others who focused on labor productivity and economic efficiency.
Step-by-step explanation:
The individual among the pioneers listed who was not making a professional impact during the Scientific Management Era is W. Edwards Deming. The Scientific Management Era, often associated with Frederick W. Taylor, was a period during the late 19th and early 20th centuries where the focus was on improving economic efficiency, especially labor productivity. Frank Gilbreth, Henry L. Gantt, Lillian Gilbreth, and Frederick W. Taylor were all key figures during this time, advocating for various aspects of scientific management in industry. W. Edwards Deming, however, made his impact later, particularly in the post-World War II era, with his principles on quality management and process improvement, particularly in Japan.