Setting the Stage for Situation Awareness

The Big Picture

An essential requirement in achieving operational excellence is foresight, particularly the ability to project awareness of the current situation forward. But what constitutes the past, present, and the many possible future projections in this regard?

To most effectively employ situation awareness in the monitoring and management of services systems, it is necessary to define a simplified conceptual model that accurately and adequately captures the big picture in terms of scenes, situations, scopes, scenarios, and scripts.

situation awareness is “the perception of the elements in the environment within a volume of time and space, the comprehension of their meaning, and the projection of their status in the near future”

Endsley, M.R, 1995, Toward a Theory of Situation Awareness in Dynamic Systems


A scene describes a snapshot of the environment and its elements at a particular moment in time. Elements can be static (unchanging) and dynamic (changing), as well as abstract (virtual) and concrete (physical). A scene is a big picture that frames an operator’s view of the environment. It is within the scene that situations unfold, from past, present, and predicted.

For an operator to maintain situational awareness, there must be real-time access to the scene and its contents, including objects (entities), relationships, and spatial and temporal aspects. For diagnostics purposes, it should be possible for an operator to explore a scene, drilling down into the structures and states of elements within the environment.

A scene is the primary communication interface for both human and machine operators.


A situation is an extended scene model focused on behavioral aspects, such as actions, events, and potentials, occurring across scene snapshots related to objects of interest and concern. While a scene is far more structural, a situation is behavioral. Many situations can exist within a scene; it is the process of signification, memory, and recognition that extracts situations from a scene, including pertinent dynamics occurring across snapshots of a scene.

A situation is a state of affairs, of circumstances and conditions. A situation can be problematic or present an opportunity for improved steering of a system towards its goals. A situation is that which has meaning and classification within a scene.

A situation is invariably subjective, reflecting the memory and learnings of both human and machine operators.


A situation is generally a partial representation of the scene via the selection of relevant information; on the other hand, it is augmented with assessment information deemed appropriate to the goals of the system and values of those steering the system.

Situations can consist of more minor nested situations that narrow the scope of operator attention based on spaces, objects (entities), relationships, and properties.


A scenario describes the temporal trajectory across a sequence of scene snapshots reflecting the unfolding of one or more situations. A scenario details various events and actions that, directly or indirectly, alter the state of elements within a scene, changing the assessment of the situation(s).

In general, a specification of a scenario while embedded within a scene is a partial representation, focused on element state changes and the reinterpretation of the situation(s).

A scenario is a storyline or storyboard that can be reconstructed from past experiences or projected trajectories. Depending on the usage of a scenario, it can be sufficient to describe it in just situations.

While a scenario can span multiple snapshots, and in this regard frame situations, the operator is nearly always starting with a situation and projecting forward in time along different scenario paths.


A script is a stereotypical representation of a sequence of actions oriented towards steering a scene and its situation from one state to another to attain a goal or maintain an operational plan. Scripts are brought into play by the occurrence of one or more recognized situations within a scene.

A situation is a pre-condition for the evaluation of a script as a potential intervention. Before selection and execution, a script is simulated to evaluate the consequences concerning goal(s).