A computer-implemented method, computer program product, and computer system are provided. The method comprises training a machine-learning model using an initial set of training data samples, receiving a new training data sample, and predicting a label for the new training data sample. The method also comprises, upon determining that a prediction quality value for the predicted label of the new training data sample is below a predefined quality value, adding the new training data sample to the initial set, thereby building an extended training data set. The method also comprises retraining the machine-learning model using the extended training data set.