Human Factors Integration (HFI)

Human Factors Integration: What is it exactly? You may be asking yourself this question if you work in a research and development or a complex systems design field. Let’s look at what human factors integration is, why it’s important, and how it can help you.

Defining the Human Factors Problem

Since at least the 1940s and the development of modern defence systems it has been recognised that the potential benefits of tools and technologies can’t be unlocked unless people can use them for the intended purposes. This is the fundamental Human Factors problem – that the hardware, products, and services that we make only become useful once they are used, and success in that depends on the capabilities and circumstances of the personnel using these tools. Summarised another way, it is easier to adapt tools and technologies to the human role than it is to try and adapt people to technology. In human factors engineering, the problem is to make systems human-centred.

This is easier said than done because the human factors problem is inherently multidisciplinary; it encompasses numerous social, behavioural, cognitive, engineering, and ergonomic sciences. The human factors design process seeks to identify how the human element interacts with a designed system for safe and effective operation of a product or service.

What is Meant by Human Factors (HF)?

It’s difficult to define human factors because there is a lack of standardization and many definitions are complex and full of acronyms and abbreviations. The term “human factors” as an applied field of study is used inconsistently across disciplines. There is no universal agreement on the span or contents of the field, but three (!) different definitions can commonly be used:

  1. Characteristics of people. The term “human factors” can refer to the psychological and physiological characteristics of humans. This is the “factors of humans” sense of the definition.
  2. Contributor to outcomes (usually bad outcomes). A typical definition of this type of human factor would be: A human factor is any attribute, characteristic, or aspect of an individual or social system that can be held accountable for a failure to perform some task or action and/or for the incidence of some condition that prevents safe operation. This definition is often used in discussions of human error.
  3. Occupation and set of practices. “Ergonomics is the scientific discipline concerned with the understanding of interactions among humans and other elements of a system, and the profession that applies theory, principles, data and methods to design in order to optimise human well-being and overall system performance.” – International Ergonomics Association (international standards definition). This is the most common definition in the UK, and is the definition favoured by the professional institutions that regulate the practice. This definition includes Human Factors as a set of methods and techniques, such as Allocation of Function Analysis, Task Analysis, Workload Analysis, Training Needs Analysis, and Manpower Assessment. We call this ‘Human Factors Engineering’ (HFE) to be clear.

Barriers to HFI Success

Companies are becoming increasingly aware of the need to improve the usability and user experience of their products. But many factors hinder their success – most notably a general lack of understanding of how to integrate HFE into new product development.

At a high-level, there is an abundance of information on HFE as an independent discipline, but the overwhelming majority of companies do not have the expertise to apply it effectively to their products.

The cost to fix or resolve these HFE failures often costs exponentially more than if they had been addressed during the product design phase, so costs can be acute. The failure to investigate these mistakes in advance can often result in a catastrophic loss of time, team effort, and resources.

  • Barriers to a successful HFE program include:
  • Lack of resources/lack of time;
  • Percieved cost and risk;
  • Not seeing the importance of the program (for example, the importance of the HFI programme in supporting the Safety Case or broader Validation and Verification (user acceptance) exercises);
  • Human Factors Engineers and contractors often have no way to benchmark performance and therefore it is difficult to demonstrate added value;
  • They have limited insights into actual usage of their work (feedback) and therefore continuous improvement is difficult;
  • They are unable to employ industry best practices as there are difficulties in reading across from academic research into practice; and,
  • Tool support for basic methods are poor or non-existant.

There are a number of reasons why these issues remain unsolved:

  • The application of HFE methods is fragmented and not consistently applied by personnel across the design lifecycle;
  • There is little learning or re-use of previous data and projects;
  • We are far from achieving even rudimentary integration with associated disciplines, including requirements engineering, reliability engineering, and safety case production; and,
  • We do not have sufficient funding for HFE research and development work in industry or government agencies to capture continuous improvement gains and validation of methods, techniques, and fundamental data.

The Human Factors Solution (HFI Approach)

What is Human Factors Integration?

The movement towards a more considered approach to HFE was first seen in the US Army MANPRINT programme of the mid-1980s. This was a proactive programme to improve the ergonomics and safety of new weapon systems under development. The response to the problem mainly focused on six domains (HF engineering, system safety, personnel, manpower, training, and health hazards) to take account of the human aspects of capability.

Human Factors Integration may be defined as a systematic process that incorporates input from all affected areas of HF and then focuses on the balanced development of both the technological and human aspects of a system to deliver the desired safety and operational capability. In human factors integration, the problem is to put together all the features that have been designed for humans and make a manageable whole out of it.

The systematic approach to HFI applies research about human behaviour and physiology to design processes. It is commonly associated with designing products to best suit the needs of people, especially those using them in complex situations.

It is critical that HFI is approached as both a technical and a management activity. Current approaches often place too much emphasis on the technical methods to be used in HFI. For us, this is the wrong emphasis. HFI, if it is to address the ‘integration’ part of its name, must be seen first and foremost as an outward-looking communication and work process control exercise.

ISO 18152 (Ergonomics of Human-System Interaction) summarises some of these management factors:

  1. Developing common terminology for HFI issues across stakeholders;
  2. Set up mechanisms for interactions across HFI issues (i.e., steering groups, standing meetings);
  3. Use suitable data formats when exchanging information with non-HF practitioners;
  4. Match tools and methods to particular projects and stages; and,
  5. Identify emerging HFI issues.

To this list we would add:

  1. Proportionality. The HFI programme should be proportionate to the risks and novelty of the system change;
  2. Timeliness. Outputs should be provided at the right time (neither too late or too early, and throughout the life cycle); and,
  3. Design iteration. Revisiting and revising solutions should be allowed for in the overall programme. This is mainly because it is difficult to predict how technology will ultimately be used ahead of time, as the introduction of the technology introduces new possibilities for how the work can adapt.

Communicating the Human Factors Solution

As we have seen, communication is the central part of HFI. We have found that the first steps in this process are often the HFI policy and Human Factors Integration Plan (HFIP).

Human Factors Integration Policy

A HFI policy is often used in United Kingdom (UK) MoD policy on HFI, as documented in JSP 912 and expected by DE&S as part of Ministry of Defence policy.
The HFI policy should set out the broad assumptions and considerations that will need to be addressed by the HFI programme, the strategy that will be used to meet these challenges, and the implications of this strategy on how the programme will be conducted (for example, in terms of resource requirements, timescales, and design iteration).
The HFI policy may not contain any details on work control or work package requirements. It is intended as an initial statement to guide development, and need not be a full Human Factors Integration Plan.

Human Factors Integration Plan

A Human Factors Integration Plan (HFIP) is an essential tool that outlines which HFI activities are needed – and which HFI activities are not needed – and how they should be integrated into the overall engineering, assurance, and project management processes. The goal is to contribute to an asset or service that will support all end users, maximise performance, and minimise the risk of human error.

The HFIP is sometimes known as the Human Factors Work Plan, Human Engineering Plan, or other terms. The content is the same, only the name is different.

A HFIP can be useful in communicating the specific requirements and process of Human Factors Integration when procuring systems.

We usually recommend a six-step approach when writing a HFIP:

  1. Clarify the programme or project context (including overarching data formats, standing meetings, quality and document review requirements, and reporting lines);
  2. Define the scope (including the nature of the change, personnel affected, remit, and lifecycle stages);
  3. Identify the obligations. Obligations means the requirements, assumptions, risks, and constraints that you have;
  4. Plan activities based on scope and obligations;
  5. Assign personnel to roles and responsibilities;
  6. Review and revise.


Human Factors Integration is often misunderstood and ineffective. This is often because it is seen as a technical exercise rather than a management exercise. And when it is approached from a management point of view, the tools and techniques that can be employed are primitive and inefficient. This is to be expected, as HF Engineers are often not trained to be managers.

We developed our HF Integration training course to address these problems, and to provide HF practitioners with the management tools and templates necessary to make HFI management easy.

We provide flexible online courses that help learners expand and improve their knowledge about human factors and usability in relation to organizational designs.