Sharing economy is a new way of coordinating economic activities that is more and more growing in importance. This economy is closely linked to collaborative platforms. This environment creates a large risk of opportunistic or even inappropriate behaviours. Therefore, it becomes important to find and select trustworthy transaction partners. The aim of this proposal is to define a model able to take into account the possibility of opportunistic behaviours of end-users in order to support decision makers in their choice of the right partner.