{"id":45490,"date":"2025-08-11T09:00:00","date_gmt":"2025-08-11T08:00:00","guid":{"rendered":"https:\/\/www.systra.com\/uk\/?post_type=expert_insights&p=45490"},"modified":"2025-08-19T15:48:22","modified_gmt":"2025-08-19T14:48:22","slug":"five-principles-to-help-you-think-like-a-human-factors-professional","status":"publish","type":"expert_insights","link":"https:\/\/www.systra.com\/uk\/expert_insights\/five-principles-to-help-you-think-like-a-human-factors-professional\/","title":{"rendered":"Five principles to help you think like a human factors professional"},"content":{"rendered":"\n

This article presents five principles to help you think more like a human factors professional when involved in the design of new equipment. The principles are based on experience from SYSTRA colleagues of practicing human factors in high hazard industries.<\/strong><\/p>\n\n\n\n

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Whilst we would always advocate the involvement of human factors professionals, particularly for complex and safety critical projects, our hope is these simple principles can help you ask the right questions, apply some basic principles, and help you to identify when you need to call in an expert.<\/p>\n\n\n\n

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This article will use a made-up project example of a customer help point to illustrate different methods and the benefits of applying each principle. Customer help points, like those typically found at train stations, are used to provide customers with service information and can be used in an emergency. Pressing the buttons will connect a customer with the appropriate person, or provide an automated response. We must stress we\u2019ve not worked on this project, merely picked it as an example.<\/p>\n\n\n\n

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Figure 1: Example project, customer help point<\/figcaption><\/figure>\n<\/div>\n\n\n
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1. Understand your users<\/h3>\n\n\n\n
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Start by identifying all the users of your new equipment. In Human Factors we refer to this as \u201cdefining the target user population\u201d. The users will vary from project to project, so identifying who they are at the outset will help you make informed decisions to suit their needs.<\/p>\n\n\n\n

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Consumer facing products, such as our customer help point, need to cater for a wide range of potential users (including different ages, shapes and sizes, strengths etc). However, for products in specialist domains your target user population may be different. Perhaps there are job selection criteria that define minimum and maximums. <\/p>\n\n\n\n

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An example of this is train drivers, who have minimum requirements for visual acuity, for obvious reasons. Here are a few tips that will help you to ensure your product or system is fit for purpose and adequately considers the capabilities and limitations of your users. <\/p>\n\n\n\n

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Consider the physical attributes of users: When considering the physical attributes of a user, human factors specialists most frequently employ a design philosophy, wherein the design is developed to account for the extreme users of the target population. This is most commonly defined as the 5th percentile female and the 95th percentile male (this can be for any piece of anthropometric data of interest, such as stature, reach, of weight). <\/p>\n\n\n\n

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Due to the normal distribution of key physical and cognitive attributes across a sample population, if you demonstrate that the design is suitable for these extreme users, you in turn demonstrate its suitability for the wider population. This concept is illustrated in Figure 2, which provides an illustration of the normal distributions of female and male stature. <\/p>\n\n\n\n

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Figure 2: Example normal distribution for female and male stature<\/figcaption><\/figure>\n<\/div>\n\n\n
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Consider cognitive and behavioural attributes: Personas are a powerful tool to consider the capabilities and goals of your target users.<\/p>\n\n\n\n

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Personas are a user-centred design approach most commonly used in user experience design, though increasingly used within the rail industry, particularly in station design. A persona is a fictional character representing a major user from your target audience. The personas will describe the users\u2019 needs, experiences, behaviours and goals. <\/p>\n\n\n\n

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The use of personas helps maintain focus on end-user needs throughout the design process. In the case of our customer help point, the personas should include a wide range of potential users, including passengers or reduced ability and mobility. A point discuss further below. <\/p>\n\n\n\n

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Consider inclusive design: Wherever possible apply inclusive design principles, this is often called \u201cDesign for all\u201d or \u201cUniversal Design\u201d. Inclusive design seeks to accommodate the widest possible range of potential users by not unduly excluding users of different abilities. <\/p>\n\n\n\n

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Readers are encouraged to use the Inclusive Design Toolkit<\/a> developed by Cambridge University1<\/sup>. Figure 3 from the afore mentioned website illustrates the diversity across the population, and the target population for inclusive design. <\/p>\n\n\n\n

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Figure 3: Target for inclusive design<\/strong><\/a><\/figcaption><\/figure>\n<\/div>\n\n\n
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The Toolkit provides the following categories for capabilities; vision, hearing, thinking, reach and dexterity, and mobility. The demands your product or system imposes can result in difficulty, frustration, or even exclusion of a much larger group of users than you probably realise. Why not use their free exclusion calculator<\/a> to see how many potential users you may be excluding.<\/p>\n\n\n\n

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At this point you may be saying \u2018inclusive design sounds great – however we do not have the budget or need on our project\u2019. In many cases the huge increase in potential customers is a compelling argument. Though it should also be noted that application of inclusive design principles will benefit all potential users, not just those with reduced ability.<\/p>\n\n\n\n

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2. Think about the tasks<\/h3>\n\n\n\n
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Make sure you identify all user tasks relevant to your new piece of equipment. A Task Analysis (TA) is one of the corner stones of human factors engineering. It is a technique we routinely employ to provide a step-by-step description of the goals, tasks, and sub-tasks associated with a product or system. <\/p>\n\n\n\n

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A task analysis can take many different forms, it is not always necessary to define each sub-task in detail. As a minimum, designers should define a list of tasks associated with their product. <\/p>\n\n\n\n

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Where a certain task is critical to the success of your product this list can then be used to derive design requirements. It can also be used as a checklist to evaluate design options, or as a more detailed evaluation of your preferred solution. <\/p>\n\n\n\n

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The TA can also be used as the basis for subsequent analyses, such as Human Error Identification (HEI) or Risk Based Training Needs Analysis (RBTNA). Error identification is discussed in more detail in principle 4. <\/p>\n\n\n\n

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Figure 4 provides an example of a Hierarchical Task Analysis (HTA), for our customer help point. An alternative example is provided in Table 1, which displays the same information in the format of a Tabular Task Analysis (TTA). <\/p>\n\n\n\n

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A key advantage of the Tabular form is the ability to add additional columns to capture information about a specific sub-task. This may include any equipment used, the information needs (i.e. what a user needs to complete this step), or task relevant contextual information (explored further in principle 3). <\/p>\n\n\n\n

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Figure 4: Example HTA for getting rail service information from customer help point<\/figcaption><\/figure>\n<\/div>\n\n\n
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Table 1: Example TTA for getting rail service information from customer help point<\/figcaption><\/figure>\n<\/div>\n\n\n
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3. Understand the context and consider the overall system<\/h3>\n\n\n\n
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It is critical you consider the context in which the tasks will be performed. This is one of the key areas of focus for HF professionals, but why is it so important? The wider workspace and physical environment have a big impact on how users interact with your product, for instance:<\/p>\n\n\n\n

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