System comprising: a heat treatment furnace; a controller coupled to the furnace for controlling one or more operating parameters thereof; and a human machine interface coupled to the controller; characterized by the following features: the controller includes a computer-readable storage device storing processor-executable instructions that, when executed, generate in real-time an estimate of a temperature of a load within the heat treatment furnace and perform a batch program, said batch program comprising a load heating phase and at least one other phase, the processor-executable instructions comprising: receiving a temperature setpoint and a load threshold via the human machine interface; collecting samples of a control loop signal when said signal is exponentially converging toward the steady-state value; fitting the collected samples with an exponential curve representing the slowest decay mode of the control loop signal; generating the estimate of the temperature of the load by mapping the fitted exponential curve to the estimate of the temperature of the load; and advancing the batch program from the load heating phase to the at least one other phase when the estimate of the temperature of the load reaches the difference between the temperature setpoint and the load threshold. a heat treatment furnace; a controller coupled to the furnace for controlling one or more operating parameters thereof; and a human machine interface coupled to the controller; characterized by the following features: the controller includes a computer-readable storage device storing processor-executable instructions that, when executed, generate in real-time an estimate of a temperature of a load within the heat treatment furnace and perform a batch program, said batch program comprising a load heating phase and at least one other phase, the processor-executable instructions comprising: receiving a temperature setpoint and a load threshold via the human machine interface; collecting samples of a control loop signal when said signal is exponentially converging toward the steady-state value; fitting the collected samples with an exponential curve representing the slowest decay mode of the control loop signal; generating the estimate of the temperature of the load by mapping the fitted exponential curve to the estimate of the temperature of the load; and advancing the batch program from the load heating phase to the at least one other phase when the estimate of the temperature of the load reaches the difference between the temperature setpoint and the load threshold. receiving a temperature setpoint and a load threshold via the human machine interface; collecting samples of a control loop signal when said signal is exponentially converging toward the steady-state value; fitting the collected samples with an exponential curve representing the slowest decay mode of the control loop signal; generating the estimate of the temperature of the load by mapping the fitted exponential curve to the estimate of the temperature of the load; and advancing the batch program from the load heating phase to the at least one other phase when the estimate of the temperature of the load reaches the difference between the temperature setpoint and the load threshold. <EOS>