Workstation Design

This article discusses the methods InterAction of Bath adopts in optimising workstation design.

A workstation designed for the anthropometry, tasks and cognitive abilities of the user is essential in realising the intended capability and safety of military systems. Unfortunately examples abound where Human Factors issues were neglected or insufficient in scope or timing, and the success of the development programme was compromised.

Burgeoning interest within the defence sector in Human Factors issues testifies to the importance of ensuring a fit between human and machine.

Standardisation

Among its various chapters, Defence Standard 00-25 explains in detail the requirements for workstation design. The stipulations within this standard are often cited in System Requirements Documents as contractual criteria that must be met. We have considerable experience translating the standard into workable recommendations to designers.

We also have detailed knowledge of ISO standards relevant to workstation design, including ISO 10075-2 (mental workload), ISO 11064 (control-room design) and ISO EN 13407 (interactive systems).

Anthropometry

The physical fit between user and workspace determines how efficiently manual tasks are performed. Well-chosen anthropometry is critical and the choice depends on the user population and environment of use. For example, the design of a vehicle cab must take account of the drivers' gender, age, type of clothing and nationality - all these things affect the size ranges expected for the user population. Furthermore, a design typically must accommodate users of dimensions between the 5th and 95th percentile, i.e. the 'middle' 90% of the user population.

Careful attention to anthropometry ensures:

• Correct positions for data displays and input devices
• Controls positioned within the reach envelopes of users
• Suitable dimensions for ease of access and maintenance
• Fewer accidents and fewer errors

InterAction of Bath uses various sources of anthropometric data for accurate design of workspaces (including MoD data and the commercial package PeopleSize). We ensure the final workstation accommodates spatial requirements of the users and the tasks they perform.

Workspaces should take account of reach envelopes of users

Examples of our work:

• Human Factors Assessment of the interior workspace layout of the Challenger II main battle tank
• Workspace design and operability assessment of a vehicle for land mine detection now in use by the US military

Control panels and control rooms

Considerations of anthropometry also apply to control panels and control rooms, but there are additional factors affecting operability here, including the layout of controls and data displays to support team work, aid understanding and maintain situational awareness.

Control panels set distinct Human Factors challenges

Specifically, much of InterAction of Bath's work in this area is aimed at:

• Supporting the operators' mental models of the process being conducted
• Presenting unambiguous information to operators
• Optimising alarm design according to established design principles
• Ensuring controls and displays are compatible with user stereotypes and expectations

Examples of our work:

• Gathering user requirements and design of the user-interface for the new generation portable radar equipment for the British Army
• Design of touch-sensitive control desks at Didcot power station

Human-Computer InterAction (HCI)

When human beings interact with computer interfaces, such as those on VDU screens, they bring with them expectations of how the computer will react to their commands and how data will be displayed. Optimising HCI is partly craft and partly science, achieved through the application of style guides, principles of human information processing and best practice, and usability assessment through prototyping.

From its very beginnings InterAction of Bath has been involved in HCI, and we hold high level expertise in designing and evaluating computer interfaces, particularly graphical user interfaces in military domains. Our main areas of work are:

• Designing menu structures and command formats
• Designing novel approaches to displaying data
• Ensuring high priority information is displayed and acted upon
• Selecting and refining data entry devices
• Creating and testing prototype interfaces
• Operability assessments

Careful HCI design results in highly operable systems

Examples of our work:

• A study of the usability of automatic speech recognition in the warship control environment, including task analysis of bridge activities
• A study of human-computer dialogue management (for automatic speech recognition) for the Defence Research Agency
• Analysis of the presentation of alarms and warnings in the Naval Platform Management System
• Assessing the human-computer interface of the 'automatic driver box' for the London Underground

Quality assurance

InterAction of Bath continually improves the quality of its services. We are certified to the quality standard ISO 9001:2000 and committed to our quality management system. We employ experienced and knowledgeable Human Factors professionals. Our reports are clear, concise, incisive, and peer reviewed.

Since 1997 InterAction of Bath has been a registered ergonomics consultancy with the Ergonomics Society and we are also registered with the Defence Standards Helpdesk.