Final answer:
Frederick Taylor and Lillian Gilbreth are credited with the development of project management techniques through their influential studies and publications on workplace efficiency and productivity.
Step-by-step explanation:
Most of the credit for developing project management techniques can be attributed to Frederick Taylor and Lillian Gilbreth. Taylor, an engineer who authored 'The Principles of Scientific Management,' is known for his time and motion studies aimed at improving workplace efficiency and management. His fundamental belief was that proper training and development would lead to the best outcome for both employer and employee. On the other hand, Gilbreth also made significant contributions to the field through her work on time and motion studies, and in determining the most effective ways to increase productivity, which she detailed in her book titled 'The Psychology of Management: The Function of the Mind in Determining, Teaching, and Installing Methods of Least Waste'. Both are considered pivotal figures in the historical development of industrial and organizational psychology, and their methods have greatly influenced modern project management practices.