Human Design is a modern synthesis, first articulated in 1987, and there is no ambiguity about that date because its founder gave it himself.
Ra Uru Hu, born Alan Robert Krakower, a Canadian formerly working in advertising and media, reported an encounter on the island of Ibiza in January 1987 with a presence he called the Voice, over eight days, during which the system was dictated to him. That is the movement's own account of its origin, and it is not offered as a scholarly reconstruction of anything older.
What the system assembles is identifiable, and the components are much older than the assembly. The sixty-four hexagrams of the I Ching supply the gates. A modified Kabbalistic Tree of Life supplies the diagram, with its ten sephiroth reworked. The chakra system supplies the centres, with the classical seven expanded to nine. And astrology supplies the input: planetary positions determine which gates are activated.
The chart, called the bodygraph, is calculated from two moments, the time of birth, and a second calculation for the point some three months earlier at which the Sun was about eighty-eight degrees of arc back, which the system calls the design and treats as the unconscious layer.
From the pattern of defined and undefined centres the system derives a Type, Manifestor, Generator, Manifesting Generator, Projector or Reflector, each with a Strategy for engaging with the world and an inner Authority for making decisions. Centres that are defined are read as consistent traits; centres that are open are read as areas where a person takes in and amplifies conditioning from others.
None of this exists before 1987 in this configuration, and the system's own literature does not claim otherwise.