SHELL Model

The SHELL model is a HFE tool that is a variation of the broader socio-technical systems (STS) approach. It is designed to help evaluate and design systems by considering how different factors interact to affect human performance and safety.

The SHELL model has four main components: Software, Hardware, Environment, and Liveware. Each component represents a different category of factors that can impact system performance and safety. By considering each of these factors in the design and evaluation of systems, the SHELL model helps to ensure that the system is optimised for human use and performance.

The model includes the following components:

• Software: This component refers to the software and user interfaces used in the system, and how they are designed to support human interaction. Software also includes procedures and rules.
• Hardware: This component refers to the physical equipment used in the system, and how it is designed to support human use.
• Environment: This component refers to the physical environment in which the system is used, including lighting, noise, temperature, and other factors that may impact human performance. This also includes the social and organisational environment.
• Liveware: This component refers to the human operators of the system, including their training, skills, and other factors that may impact their performance.