Abstract
Humans introduce new technology into homo-technological systems, as new reactors or any new product. The risk of failure is dependent on our experience, either through technical development and design mistakes and errors, or the product does not have a sufficient competitive advantage in the market. We review the learning curves that are now well known and established for both accident event analysis and product price reduction. We present the facts behind the integral contribution of human error to accidents and risk, and provide the theoretical analysis of outcome rates (undesirable event and cost reduction) based on the Learning Hypothesis. The importance of the accumulated experience on the learning rate, and the depth of experience on the distribution of outcomes, is presented.