Other models von Neumann used or planned to use:

• The Kinematic Model
• Hard to treat formally
  
  
• Cellular Automata
• Produce a Universal Constructor (UC)
  
  
• Excitation-Threshold-Fatigue Model
• Replace the finite automata occupying each cell of the UC by a suitable neuron
  
  
• Continuous Model
• Write partial differential equations for this neuron
  
  
• Probabilistic Model
• Introduce probabilities to obtain a stochastic or probabilistic model
  
  

These models represent successive stages in a (projected) research sequence. However, von Neumann stopped working on this topic in 1953, and died in 1957, so the work did not progress beyond Cellular Automata.