  We introduce the concept of compactly representing a large number of state
sequences, e.g., sequences of activities, as a flow diagram. We argue that the
flow diagram representation gives an intuitive summary that allows the user to
detect patterns among large sets of state sequences. Simplified, our aim is to
generate a small flow diagram that models the flow of states of all the state
sequences given as input. For a small number of state sequences we present
efficient algorithms to compute a minimal flow diagram. For a large number of
state sequences we show that it is unlikely that efficient algorithms exist.
More specifically, the problem is W[1]-hard if the number of state sequences is
taken as a parameter. We thus introduce several heuristics for this problem. We
argue about the usefulness of the flow diagram by applying the algorithms to
two problems in sports analysis. We evaluate the performance of our algorithms
on a football data set and generated data.
