Synopsis Organising is one of the oldest human activities. It is a phenomenon that will continue to be important to people. This is based on the assumption that organisation influence human behaviour and individuals influence an organisation's behaviour. Organisation development also assumes that both individual behaviour and organisational behaviour can be modified and done so with favourable results. Organisation developments deals with organisation aspects of the behavioural sciences and may be known as, or associated with human resource development organisation behaviour, psychology and renewal. The definition of an organisation as used in this book is two or more persons interacting within some mutually recognised power relationship for some common purpose. This definition is intentionally broad in order to include all sizes and types of organisation formal as informal of either a temporary or more permanent nature.