The level of readiness of an organisation to join a collaborative process depends on 'hard' factors such as competency fitness or technological compatibility, but also on several other factors of a 'soft' nature such as an organisation's character, willingness to collaborate, or affectivity/empathy relationships. Considering these aspects, a modelling approach to assess how prepared an enterprise is to join a collaborative network is proposed. The approach is based on the notion of 'character' of the organisation, addressing behavioural aspects regarding collaboration. The distinction between collaboration readiness and preparedness is established. In order to deal with the incompleteness of information and uncertainties associated to the readiness assessment process, it is proposed to use belief networks, which allow performing inference concerning behavioural characteristics of organisations. The approach is then extended in order to handle decision making under situations characterised by uncertainty. An example illustrates how the approach can be integrated in a partner's suggestion mechanism.