Hello all, I am trying to implement a discrete event siumulation for a logistic network. To do this, I need a representation of the network as such and a way to express what each Process does when it gets alerted by an event. A Process has inputs and outputs which are again connected to outputs and inputs of other Processes. Establishing these connections constructs the network as such. But the Processes also need to do something. They need to take something from one of their inputs, so something with it and place something on one of their outputs. So I kind of have a dual usage for inputs and outputs: they play a role in the topology of the network and in the "function" which defines a process. How can I keep the two in sync? Is there a way prevent a Process from trying to use an output which does not exist? What would be a good way to represent a Network anyways? I believe the classic approach is a list of nodes and a list vertices. In the simulation I will frequently have to find the process of an input or output and to find the input connected to an output. The node/vertices implementation seems to require scanning lists, which could be slow once I have thousands of processes. Other than that any pointers to how to construct networks (which go beyond mere graphs) would be much appreciated. -- Martin