Assessment of different types of risks is today one of the challenges for an Integrated Risks Analysis (IRA) methodology. Indeed, whereas technical or environmental risks assessments can generally be done by means of statistical way, human and organizational considerations are more taken into account with the use of expert judgments. These considerations lead, from a scientific point of view, to address issues such as how the information provided by the experts can be collected and then modeled. Thus, this paper aims at reviewing different ways needed to express expert knowledge but also different frameworks for representing the information collected. These two items have to support the full development of the IRA methodology.