Christaller made a number of assumptions such as:
All areas have
- an isotropic (all flat) surface
- an evenly distributed population
- evenly distributed resources
- similar purchasing power of all consumers
The theory points out that to prevent spheres of influence overlapping or having gaps, the best shape was a hexagon.
The breaking point is where the consumer is equidistant from two/more similar services i.e. where the consumer is equally far from two or more centers.