Marker Dependencies.

Some dependencies might function as markers for particular characteristics of environments. For example, severely resource constrained environments might be characterized by resource contention failures repeating over and over, leading to the observed dependency that one resource contention failure leads to another. We would expect this dependency to appear in any type of resource constrained environment, however superficially different, whether it is a transportation planner, an air traffic control system, or a forest fire fighter dispatcher. To look for such markers, we will need to describe a hierarchy of failures and actions such that dependency sets for different task environments can be compared.