Building the Great Pyramid in 20 years—the commonly accepted time frame—would have required placing 1.1 blocks in their final resting place every two minutes, over a work schedule of 365 days a year, if the block-laying were continuous for 10 hours per day.
Recent evidence has been found that suggests the workforce was paid, which would require accounting and bureaucratic skills of a high order.
Nineteenth-century Egyptologist William Flinders Petrie proposed that the workforce was largely composed not of slaves, but of the rural Egyptian population, working during periods when the Nile River was flooded and agricultural activity was suspended.
Egyptologist Miroslav Verner posited that the labor was organized into a hierarchy, consisting of two gangs of 100,000 men, divided into zaa or phyle of two hundred men each, which may have been further divided according to the skills of the workers.
More buildings and complexes are being discovered by The Giza Mapping Project.
Several hundred feet southwest of the Great Pyramid lies the slightly smaller Pyramid of Khafre, one of Khufu's successors who is also commonly considered the builder of the Great Sphinx, and several hundred feet further southwest is the Pyramid of Menkaure, Khafre's successor, which is about half as tall.