What is designing for people?
Designing for people is a design process that focuses on the needs and characteristics of the users or operators.
Good design takes into account how the operator is expected to interact with the workplace set up, the work equipment and how the work equipment fits into the system as a whole. As a result, facilities, hardware, systems, equipment, product tooling, materials, layout and configurations are adapted to human skills, limitations and anatomy.
The design process requires an analysis of the work tasks that operators have to carry out and the effect of any constraints that the design and its influence on the environment (e.g. noise, vibration) is likely to have on the operator’s health, safety and well-being.
Consistent with the focus of other human and organisational factors, designing for people focuses on three aspects – the individual, the machine and the work environment.
Why is designing for people important?
The design of control rooms, alarm systems, plant and equipment has a huge impact on human performance; that is, the likelihood of people performing their tasks as planned. Designing tasks, equipment, processes and the work environment to suit the user can reduce human error, accidents and ill health, and increase likelihood of achieving desired performance.
The earlier that the intended operator is considered in the design process, the better the results are likely to be. The objective is to design machinery in the context of the work system with human capabilities and limitations in mind. This, in general, is the principle of ergonomics.
What is the role of ergonomics in designing for people?
Ergonomics is a science concerned with designing and arranging tasks, equipment and workstations so that they interact most efficiently and safely with the people that use them. It is a person-centric approach, putting people first by taking account of their capabilities and limitations and applying these learnings in the design process.
Designing tasks, equipment and workstations to suit the user can reduce human error, accidents and ill health. Failure to observe ergonomic principles can have serious consequences. Effective use of ergonomics will make work safer, healthier and more productive.
Manual tasks are recognised as a major occupational safety and health risk in workplaces. Manual tasks are any activities or sequence of activities that require a person to use their physical body to perform work, including:
- manual handling – the use of force in lifting, lowering, pushing, pulling, carrying or otherwise moving, holding or restraining any person, animal or thing
- performing repetitive actions
- adopting awkward or sustained postures
- using plant, tools or equipment that expose workers to vibration.
A scoping study by the Department advised that manual task injuries – specifically musculoskeletal disorders (MSD) – account for approximately one third of all injuries occurring on Western Australian mine sites, with about two thirds of manual task injuries defined as ‘serious’ (i.e. 14 or more days lost from work).
A well-designed work area, work procedures and ergonomically designed equipment will help eliminate or reduce risk factors associated with hazardous manual tasks.
In the context of designing for people, effective consultation involves implementing the participative ergonomics approach. Participative ergonomics refers to the process of involving workers in improving their workplace to reduce injury and increase productivity. With firsthand experience of performing the work on a regular basis, workers are best placed to undertake the risk management process relating to their work.
The benefits of the participative ergonomics approach include:
- better identification of hazardous manual tasks, risk assessment and solutions because of the workers’ hands-on and relevant knowledge and experience with the task
- worker ownership of the process, resulting in increased support for implementing control measures
- improved teamwork and cooperation
- positive impact on the workplace safety culture.
How can we design for people better?
Designing safe, effective and productive work systems for people involves considering:
- the work environment
- equipment ergonomics
- human machine interface
- alarm management.
Using ergonomic design principles to manage lighting, thermal comfort, noise, vibration and atmospheric contaminants
The work environment can impact on a person’s health and performance in a number of different ways, including:
- effects that damage health (e.g. heat stress, hypothermia/hyperthermia, noise-induced hearing loss, inhalation of hazardous dusts, chemicals, mists and fumes, hazardous manual tasks and whole body and hand-arm vibration)
- effects that reduce the individual’s ability to perform a task (e.g. poor lighting, distraction, noise and vibration).
Furthermore, the design of machinery should also take into account the effects any emissions from the machinery may have on the operator or on the work environment, such as airborne contaminants in the form of fumes, vapours, gases, mists and dusts.
Applying ergonomic design principles to enhance access to equipment, prevent musculoskeletal injury, and promote engineering solutions that make equipment easy to use
AS 4024.1401 Safety of machinery – Ergonomic principles outlines the factors and methods for incorporating ergonomic principles into the design process of machinery. It states that people’s ability to safely use the machinery is dependent on their proportional and geometric relationship to it. Information on population body dimensions allows the designer to design a machine so that it is ergonomically relevant to its user, such as ensuring adequate reach or sufficient clearance for the operator.
Machinery should be designed to take account of the variability in operator characteristics, including:
- body dimensions
- body movements
- physical strength
- mental abilities.
Using ergonomic design principles for control rooms and vehicle cabs
Human-machine interface refers to the interactions between the human, the machine and the environment, and is an important consideration in designing for people.
The overall principle which concerns human-machine systems is that the machine and its associated elements (i.e. displays, controls, instructions, etc.) shall be suitable for the operator and the given task. In order to realise this principle, the machine system should consider human characteristics, with respect to physical, psychological and social aspects.
Some of the ergonomics principles recommended in AS 4024.1401 when there is interaction between operator and machinery are:
- Suitability for the task – machinery should support the operator when performing repetitive tasks. The operator should be supported in such a way that the operation does not overload or underload their mental abilities.
- Self-descriptiveness – underlying process and the functioning of the machinery should be easily understandable for the operator.
- Controllability – operator should have control over the machine and its components.
- Conformity with user expectations – machinery should be, as far as possible, compatible with the operator’s expectations based on previous work experience and training.
- Error tolerance – machinery should be error tolerant and provide the operator with the means for handling errors so that an error does not lead to a hazardous situation.
- Suitability for individualisation – machinery should allow the operators an appropriate degree of autonomy with regard to decisions on priorities and procedures.
- Suitability for learning – machinery should allow the development of existing abilities and the attainment of new skills.
- Flexibility – machinery should be flexible enough to be adapted to the variation of the skills within the operator population and, if necessary, to special needs.
Applying ergonomic design principles to manage alarms and prevent alarm floods
The design of the interaction between the operator and the machine should consider the following questions:
- Are alarm systems designed to ensure maximum usability?
- Is information needed to perform the task readily available to the operator? This information should be presented in such a way that the operator can readily understand and act on it. For example, providing a quick overview of the whole work system as well as detailed information on key parts and components.
- Are displays and signals designed in a manner compatible with the characteristics of human perception and the task to be performed?
- Where an interactive system is used, are icons, symbols and commands consistent in appearance and function?
- Are visual deficiencies accounted for? Colour should not be the only sort of coding. Shape, position, symbols and text should also be used.
- Where it is not possible to rely on auditory signals, are signals other than acoustic ones (e.g. visual, tactile) considered?
- Do controls and displays clearly correspond with their functional output?
These DMIRS webpages cover various aspects of safe design including safe design principles for risk management, verification process and effects of design changes.
This DMIRS webpage provides information on manual tasks, what makes them hazardous and how to manage the risks associated with hazardous manual tasks. It provides resources, including information sheets on various manual task topics (e.g. participative ergonomics).
This code of practice by SafeWork Australia provides practical guidance to organisations on how to manage the risks of musculoskeletal disorders arising from hazardous manual tasks in the workplace.
These documents by the UK Health and Safety Executive (HSE) provide information on how ergonomics can improve human safety, case studies on ergonomic design, and practical ideas on how to identify, assess and control risks arising from human factors.