Beginning with Djoser who ruled from 2687-2667 BCE, three other massive pyramids were built - the Step pyramid of Saqqara (believed to be the first Egyptian pyramid), the Bent Pyramid, and the Red Pyramid.
There was a town for the workers of Giza, including a cemetery, bakeries, a beer factory and a copper smelting complex.More buildings and complexes are being discovered by The Giza Mapping Project.Some research suggests alternate estimates to the accepted workforce size.For instance, mathematician Kurt Mendelssohn calculated that the workforce may have been 50,000 men at most, while Ludwig Borchardt and Louis Croon placed the number at 36,000.19th 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 suspended.
Egyptologist Miroslav Verner posited that the labor was organized into a hierarchy, consisting of two gangs of 100,000 men, divided into five zaa or phyle of 200 men each, which may have been further divided according to the skills of the workers.
Most sources agree on this number of blocks somewhere above 2 million.
The Egyptologists' calculations suggest the workforce could have sustained a rate of 180 blocks per hour (3 stones/minute) with ten hour work days for putting each individual block in place.
The accepted values by Egyptologists bear out the following result: 2,400,000 stones used ÷ 20 years ÷ 365 days per year ÷ 10 work hours per day ÷ 60 minutes per hour = 0.55 stones laid per minute.
Thus no matter how many workers were used or in what configuration, 1.1 blocks on average would have to be put in place every 2 minutes, ten hours a day, 365 days a year for twenty years to complete the Great Pyramid within this time frame.
Using modern equipment, the study concludes:“Utilizing the entire Indiana Limestone industry’s facilities as they now stand [for 33 quarries], and figuring on tripling present average production, it would take approximately 27 years to quarry, fabricate and ship the total requirements.” Booker points out the time study assumes sufficient quantities of railroad cars would be available without delay or downtime during this 27 year period and does not factor in the increasing costs of completing the work.