Risk assessment involves the probabilities of events and degrees of severeness.
In a simple example the project leader og project team reach consensus on both events, probabilities and severeness and then calculate risks. Risk of an event is Severeness of an event times Probability of the event. (R=P x S) However the dynamics in the project group will become an indirect dominant factor, which might bias the assessment severely.
Why not use a Bayesian inspired approach, a simple statistical calculation, which in the process also quantifies team-dynamics in the face of the project leader…
Each member rank all members of the project team in relation to overall project insight – ties are allowed, scale is determined by number of project members. So in a highly hierarchical team of five members each team member will use the numbers from one to five during ranking. In a more level team of five members there will be use of ties, i.e. some will write three alongside all members, some will write one and a half two times insted of the numbers one and two, four three times instead of three, four and five, etc. Rankings are added and corresponding weights calculated and assigned to each member, but only made visible to a secretary/facilitator or the project team leader.
Along the note of rankings each member of the project team hands in a named list of all relevant critical events and corresponding risk probabilities and degrees of severeness. Using weights from internal rankings the risks are then calculated as weighted averages. In the process some events might be grouped and qualitatively redefined during a project team session. The process can then be repeated (new lists are created) or the facilitator or team leader may choose to adjust previous numbers and calculations.
Note use of the word insight, a term less colored by political or psychological positioning compared to other alternatives. Futhermore people might have difficulties or hesitate to grade other people using numbers directly. Then make a color scale and let the facilitator or project team leader translate colors into numbers in intermediate calculations.