Briner et al. (1990) divide the project team membership into ‘visible’
team members that are part of the organization but not permanently in
the project, and ‘invisible’ team members that are stakeholders in the
project while non-members of the organization. Examples of the latter
would be subcontractors and suppliers. The heart of the visible team
is the core team that is permanent but not necessarily full-time. Other
visible team members are temporary in the project. According to this definition,
project team membership does not necessarily involve mutual
social awareness, commitment to the common goal, the same performance
norms, or accountability for the outcomes (Mäkilouko, 2001).