A Review of Building Evacuation Models - NIST Virtual Library

A.30 E-SCAPE
Developer: E. Reisser-Weston, Weston Martin Bragg Ltd, UK
Purpose of the model: The purpose of this model is to view evacuation in real time, identify
bottlenecks in the building configuration, and to gain a probabilistic view of the emergency
scenario by running the model several times 116 . This model has been complied from studies
carried out on emergency evacuation from over 30 years ago.
Availability to the public for use: The availability of the model is unknown at this time.
Modeling method: This is a behavioral model.
Structure of model: This is a coarse network system. Each room or area in a room is
represented by a node, and the arcs connect these as well as represent the distances between the
nodes.
Perspective of model and occupant: This model seems to view the occupants with an
individual perspective. It is unclear whether or not the user inputs individual characteristics of
the occupants, but it seems that the model recognizes individual responses to the evacuation
environment, according to their Performing Shaping Factors (PSFs).
The occupants have an individual view of the building, because their choice of egress route is
affected by the evacuation environment and PSFs. The occupants’ choice of route to the exit is
affected by the distance of the occupant to the exit, the frequency of use of the exit during
normal situations, and the signage of the route.
Occupant behavior: The model attempts conditional behavior. The model incorporates the
method of Hierarchical Task Analysis (HTA), which involves sorting evacuation into individual
tasks and then decomposing these tasks into sub-tasks until the appropriate level of analysis has
been reached. Factors of the environment determine the probability of an individual carrying out
certain tasks during the evacuation. E-SCAPE recognizes the following four factors that shape
an evacuation (these are known as Performing Shaping Factors – PSF):
• Structural PSF: The organization of the work environment, such as physical characteristics,
rules, hierarchies
• Effective PSF: The emotional, cultural, and social factors that affect decision-making during
an evacuation
• Informational PSF: The information available to occupants from direct collection or its
communication
• Task and Resource Characteristics PSF: The tasks being carried out by the occupants that
may in turn affect their ability to react to certain cues/stimuli.
A-106