Core competencies of small and medium sized enterprises (SMEs) are grounded on skilled manpower and therefore occupational health and safety plays an important role on performance achievement. While traditional risk assessment methodologies are mainly centred on machine ways of failure rather than on potential injuries for workers and require significant resources not available in SMEs, we developed a bottom up method in order to allow safety analysts to follow a standard path, not much time-spending due to a semi-probabilistic approach and enabling identification of hidden risks. Risk Analysis by Threshold Evaluation (RATE) is aimed to help entrepreneurs assessing the capacity of their system to reach a desired safety level and evaluate how additional safety measures can improve safety performance.