Product Development, Human factors engineering

HFE Practice Models: How Manufacturers Establish and Maintain HFE Competency

By Allison Strochlic, Michael Wiklund
Product Development, Human factors engineering

Manufacturers can rely upon internal human factors engineers and/or external consultants to apply HFE effectively during device development.

UL’s human factors engineering (HFE) team has provided HFE support to more than 100 medical device and combination product manufacturers. In some cases, we have augmented a manufacturer’s internal capacity, teaming up with one or more in-house HFE specialists to conduct a usability test or develop a key HFE end-product (e.g., HFE/UE report developed for FDA submission). In other cases, our team has performed HFE Learn more about human factors engineering at the MedTech Product Development Conference | September 29-30, 2016 | Attend in-person or virtually | REGISTER HEREtasks in a more turnkey manner, executing an entire program of HFE activities from start-to-finish with only intermittent input from the manufacturer.

We most often see manufacturers execute HFE in one of the following four ways, ordered by level of a client’s in-house HFE capabilities and capacity:

  1. An internal “broker” engages with external HFE consultants to perform virtually all of the hands-on work.
  2. Internal HFE specialists (perhaps two or three) perform some of the HFE work and engage HFE consultants to perform selected activities, including some that might benefit from an outsider’s perspective.
  3. Internal HFE specialists form a centralized team and consult with project teams as needed.
  4. Internal HFE specialists are embedded within project teams and perform mostly product-specific HFE activities.

Importantly, each of the above approaches requires someone within the organization to take the helm and, at a minimum, direct and oversee the HFE work performed by others, regardless of whether those individuals are internal or external HFE specialists.

The balance of this article briefly describes each model and presents some of the key pros and cons associated with its implementation.

Model 1: Internal HFE broker

In accordance with this “minimalist” model, a single manufacturer representative engages and directs the work of external HFE consultants. This “broker” might not necessarily be an HFE specialist, but rather is oftentimes someone with a product development, engineering or regulatory affairs background who has been tapped to serve as the organization’s HFE liaison. It is most effective when the individual sincerely and fully embraces the HFE management responsibility, believes deeply in the value of HFE, and has abundant energy to ensure that HFE is applied correctly and consistently. Through close collaboration with experienced consultants, perhaps supplemented by self-study and/or participation in industry events, a broker can gain a strong understanding of core HFE principles and be well-prepared to manage and assess the work of others.


  • Reduced overhead cost due to lack of internal team
  • HFE bandwidth can be scaled up or down as needed through the engagement of external HFE consultants


  • Limited “corporate memory” for HFE work
  • Limited capacity to oversee parallel HFE work streams (and, perhaps tend to other duties)
  • Potential lack of higher-level HFE knowledge and strategy
  • Potential for inconsistency among HFE methods and end-products (if engaging multiple consultants)
  • Increased costs of engaging consultants as compared to leveraging internal resources

Model 2: Internal HFE Specialists + Consultant support

The most common model we encounter within client organizations is one that blends internal and external HFE expertise. According to this model, a handful of internal HFE specialists perform HFE activities throughout a product’s development and engage external resources as needed to supplement their internal capacity. We find that manufacturers who have implemented this model most often call upon external HFE consultants when they (1) need to conduct usability testing (a multi-week effort including test planning, execution, and reporting), and (2) seek an independent opinion (i.e., sanity-check) on a product’s design, HFE method, and/or HFE end product.

For example, in the latter above scenario, HFE consultants might be asked to review and comment on a summative usability test plan or HFE/UE report before the critical documents are submitted to FDA for review.


  • Sufficient internal capacity to help ensure that HFE expertise is applied consistently throughout product development
  • Internal specialists can delegate some tasks and focus their efforts on tasks for which they add the most value
  • Helps a company develop a foundation of HFE knowledge and experience
  • Consultants can serve as allies, supplementing and supporting internal specialists’ opinions
  • Consultants often offer a broader perspective on HFE, leveraging experience serving many clients that develop different types of medical devices


  • Potential for inconsistency in how HFE is practiced and the resulting end-products (if engaging multiple consultants)
  • Increased cost of maintaining internal team in addition to engaging external consultants

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About The Author

Allison Strochlic, UL

About The Author

Michael Wiklund, UL