Abstract: A computerised tool for assessing scenarios is arranged to allow a user to select a placement for an icon representing a scenario on a matrix representing, along respective axes thereof, the likelihood of the scenario and the impact of the scenario. The tool is further arranged to display information relating to placements for said scenario selected by previous users. The tool is also further arranged to allow said user to select one or more likelihood influence indications representing actions which have been taken or may be taken to influence the likelihood of the scenario from a plurality of available likelihood influence indications and to display the selection of likelihood influence indications by previous users.