This paper explores how the dynamics of complex biological processes can be modelled and simulated as an organisation of multiple agents. This modelling perspective identifies organisational structure occurring in complex decentralised processes and handles complexity of the analysis of the dynamics by structuring these dynamics according to an organisational structure. More specifically, dynamic properties at different levels of aggregation in the organisational structure are identified, and related to each other according to the organisational structure. The applicability of this organisational modelling approach to address complexity in biological context is illustrated by a case study: the organisation of intracellular processes.