Because biochemical networks tend to be very large and dense, a crucial point is their concise and unambiguous representation and the development of computational methods to model and analyse them in an efficient manner. Before starting a quantitative analysis, a qualitative analysis can check the model for consistency and correctness of its biological interpretation. For this step we propose methods which are based on Petri nets.

Petri net theory was developed for modelling, analysing, animating, and simulating systems with causal concurrent processes. The theory provides a definite description of complex networks and methods for analysing and simulating them. We have applied these methods to validate metabolic networks as well as signal transduction pathways. The talk gives the basic ideas behind this application.