In late 19th century, in the United States, large-scale government projects were the impetus for making important

decisions that became the basis for project management methodology such as the transcontinental railroad,

which began construction in the 1860s. Suddenly, business leaders found themselves faced with the daunting task of organizing the manual labor of

thousands of workers and the processing and assembly of unprecedented quantities of raw material. 

Near the turn of the century, Frederick Taylor began his detailed studies of work.

He applied scientific reasoning to work by showing that labor can be analyzed and improved by focusing on

its elementary parts that introduced the concept of working more efficiently, rather than working harder and longer. 

Taylor's associate, Henry Gantt, studied in great detail the order of operations in

work and is most famous for developing the Gantt Chart in the 1910s.

A Gantt chart is a popular type of bar chart that illustrates a project schedule and have become a common

technique for representing the phases and activities of a project work breakdown structure,

so they can be understood by a wide audience (Figure 1.3).

Although now considered a common charting technique, Gantt charts were considered quite revolutionary at the time they were introduced.

Gantt charts were employed on major infrastructure projects including the Hoover Dam and the Interstate

highway system and are still accepted today as an important tool in project.