Because there are no pure formal or informal organisations in real world, one may conclude that an organisation is a mix of formal and informal groups. Thus, its performance depends on the management ability to recognise the existence of these groups, to transform them from groups into working teams, to motivate and stimulate them to achieve organisation’s goals. We must differentiate the concept of group versus the concept of team. A simple definition of the group can be: two or more persons who come into contact for a purpose and who consider the contact meaningful. A team has to accomplish bigger goals than any individual group. The purpose of a team is to perform, achieve results and be successful in the organisation or marketplace. The...