Henry L. Gantt's contribution to management is that he Multiple Choice suggested that humans have five levels of needs. stressed the importance of hiring and training the proper worker to do a job. suggested that frontline supervisors would be motivated if they received a bonus for each of their workers who completed their assigned daily tasks. emphasized the application of quantitative analysis to management decisions and problems. developed a system to lower costs and increase worker productivity by showing how employees could work smarter, not harder