SHELL model is be defined as an abstract replica of individual factors that makes clear the extent aviation individual factors and aiding in realizing the individual components association among individual parts of an aviation (individual subsystem) and environmental aviation (flying subsystem) (Keightley,2004). Edwards (1972) first developed the model that was afterwards modified to a building wedge formation by Hawkins (1984) (Hawkins & Orlady, 1993). The word SHELL is the initials of Software, Hardware, Environment and Liveware and seats more emphasis on individuals and individual interface with components of other aviation system (Johnston, McDonald & Fuller, 2001).
This models adopted system perspective proposes that individuals are not to blame for cause of accidents. Various contextual and duty associated factors that intermingle with individual operation within aviation system to impinge on operational performance are taken into consideration in the systems perspective thus the model deems on both active and dormant malfunction in aviation system. All SHELL model components embody a building wedge of individual component learning in aviation. The individual element forms the vital and flexible constituent of a system, directly intermingling with components of other systems. The general ability and restrictions of the central individual component must be clearly understood to shun stress and breakdown in the aviation system (Hawkins & Orlady, 1993).
The human characteristics include the physical shape and size being body movement and measurement, fuel requirement being food,water and oxygen, input characteristics being individual senses, information processing being capacity for working memory, output characteristics being decisions and communication after the input and environmental tolerance being the bodily environmental factors (Hawkins & Orlady, 1993). The three uses of the SHELL model are; 1.Training tool where the model helps aviation institute better their training intercession and the effectiveness of institute preserve against mistake. 2. Safety analysis tool where the model is used to comprehend methodical individual factors association throughout operational audits aimed at minimizing mistakes and enhancing well-being. 3. Licencing tool where the model is used in helping making clear individual performance wants, ability and constraint thereby enabling ability to define from a protection administration perspective (Hawkins & Orlady, 1993).
In conclusion it is therefore clear that the SHELL models symbolize a building wedge of individual component learning within aviation.