A model category for local po-spaces
  Locally partial-ordered spaces (local po-spaces) have been used to model concurrent systems. We provide equivalences for these spaces by constructing a model category containing the category of local po-spaces. We show the category of simplicial presheaves on local po-spaces can be given Jardine's model structure, in which we identify the weak equivalences between local po-spaces. In the process we give an equivalence between the category of sheaves on a local po-space and the category of etale bundles over a local po-space. Finally we describe a localization that should provide a good framework for studying concurrent systems. 
Peter Bubenik and Krzysztof Worytkiewicz