The BTL survey follows a strict methodology, developed by a group of consultants specialised in leadership, which established the study components, the skills and personal characteristics for analysis. These components have been certified by the Portuguese people management association (APG) and afterwards gathered the weights per component from a sample of 100 Portuguese leaders of recognised standing. Such procedure ensures total precision in the analysis conducted, as far as it is based on scientific criteria and not mere subjective opinions, which is exempt and impartial.