if (action->type == SIMIX_ACTION_EXECUTE){
surf_workstation_model->set_category(action->execution.surf_exec, category);
}else if (action->type == SIMIX_ACTION_COMMUNICATE){
if (action->type == SIMIX_ACTION_EXECUTE){
surf_workstation_model->set_category(action->execution.surf_exec, category);
}else if (action->type == SIMIX_ACTION_COMMUNICATE){