A processing apparatus includes a precursor detection unit that detects a precursor event indicating a precursor that a target process cannot be executed by a process unit, and a control unit that sends a preparation request to a substitution processing apparatus when the precursor detection unit detects the precursor event in which the preparation request requests the substitution processing apparatus being a ready state for starting a substitution processing. The control unit sends a termination request to the substitution processing apparatus when a predetermined condition is satisfied after the control unit sends the preparation request, in which the termination request requests the substitution processing apparatus terminating the ready state.