Notes:

Bionicle ended in 2010, and Hero Factory began shortly thereafter. The official Bionicle storyline "ended" with Mata Nui, defeating Makuta and surrendering his own mechanical body to heal the planet Bara Magna, dying in the process. His spirit remained alive, but his mechanical body died and became a continent-size hunk of metal. The surviving Toa, Matoran, Glatorians, and Agori from all the previous toy lines settled down on the newly-formed Spherus Magna and started a new society, constructing a technologically advanced city from the remains of Mata Nui's body. This city would come to be known as……..

Makuhero City.

With Makuta dead, the Toa and Glatorians retired after decades of fighting evil, and presumably lived peaceful lives in the new city. Though Makuta had been destroyed, many of his creations still remained on Spherus Magna causing chaos and disrupting the new society. These rampant creatures would come to be known as "villains" that would later plague the city. Thus, the Matoran and Agori, using weapons from the retired Toa as well as technology from Mata Nui, created new mechanical warriors to fight for them and keep the peace in the city as replacement Toa.
These new robotic warriors would come to be known as………heroes.

Thusly, Hero Factory is actually a direct continuation of the Bionicle storyline.