Nothing stands without structure.
Objects in nature and those that are made by humans have structure. The same is true for application user interfaces. In this post, we describe UI Structural engineering and review its function in the creation of websites and other digital forms of communications, products, and services.
Why is structure important?
The structure of an object provides a function of support. For example, bones, joints, and muscles provide structure for the human body. Consider how your performance would diminish if your bones, muscles, and joints were moved around, compromised, or even removed? Likewise, application user interfaces have a structure that should be carefully considered and maintained. If not, the intended performance of a user interface design can be compromised.
What is UI structural engineering?
In Project Accountability Model for UI Teams, I describe engineering activity as an effort to rationalize a structure in support of a design solution. Hence, UI structural engineering is concerned with defining the structure of application user interfaces.
UI structural engineering is concerned with defining the structure of application user interfaces.
To illustrate the value of UI engineering, it helps to understand how it contrasts with other key activities. My research in project accountability proposes four project-level activities: UI architecture, UI Design, UI engineering, and UI production.
For instance, framing the underlying intention of a project is considered an architectural activity. And the individuals who create the solution to satisfy the plan derived from architecture activity participate in design. 
Architecture and design artifacts are but aspirations until their underlying structure can be rationalized. The effort to define the structure is an act of engineering. And together, architecture, design, and engineering provide the plan to enable production.
Architecture activity frames project constraints to provide scope clarity and articulate explicit intentions for the project.
Design activity is a multi-disciplinary effort that satisfies the intent of architecture and is heavily dependent on structural constraints.
Engineering activity assesses contextual conditions and models the required structure to optimize design performance.
Production activity produces the consumable product that’s used by the targeted audience.
Core UI Team Activities for Creating Effective Digital Interfaces
© 2020 Nathaniel Davis | Methodbrain
Lastly, production activities translate architecture, design, and structural documentation into artifacts that are consumed by technology infrastructure and delivered as an interface on a computing device.
Overall, UI structural engineering is an essential function in the creation of digital user interfaces. Acknowledging this fact helps organizations better address the growing complexity of their digital interfaces.
How is UI structure created?
The conceptual reasoning of humans influences the creation of any application user interface. Hence, a user interface inevitably reflects the human concepts that shape it. If the conceptual assertions used to define the behavior of an interface are sound, the interface has a higher probability of performing as intended. If the underlying concepts are flawed, the performance of the user interface will more than likely follow suit. In every case, the aggregate of all underpinning conceptual relationships of a user interface defines its structure. 
…a user interface inevitably reflects the human concepts that shape it.
There are two classes of UI structures: conceptual structure and physical structure. Physical UI structures offer traceability and methods for systematic intervention and management. UI structures that are documented using static (unstructured) methods and lack systematic intervention have a conceptual UI structure. Most organizations still rely on static, conceptual methods to maintain UI structure. But this is unsustainable at scale, can create considerable waste, and lowers structural performance in complex UI environments.
Can the structure of a user interface fail?
Yes, similar to physical buildings, the structure of user interfaces can fail. When a UI team does not properly account for UI structural integrity, the user interface can impede users from achieving their business-aligned objectives. In other cases, an interface will become completely unusable for some users. These are clear indicators of compromised or failed UI structure.
Conversely, a sound UI structure avoids the possible “collapse” of usability. Overall, structural integrity helps to improve UI design outcomes and reduces unnecessary iteration on failed features. It also lowers business risk and saves teams time and money.
What makes for good UI structural engineering?
Context, human behavior, and language directly impact the nature of a website’s UI structure. The analysis of each reveals human-centered concepts and content that are essential for digital engagement. UI structure is created when the aggregate of these concepts and content are systematically related to serving as the blueprint for the desired UI behavior.
Conceptual modeling is the primary method for planning UI structure. The resulting models should express more than the constructs for navigation, labeling, and content organization; UI structure documentation should include models for who, what, where, when, why, and how content is displayed.
As an interactive environment scales in scope and complexity, defining and maintaining UI structure requires operational maturity. Meaning, the UI structure must be 1) manageable, 2) measurable, and 3) allow for documentation that promotes referencing and traceability. For example, Methodbrain uses specialized software to design UI structure and evaluate UI structural integrity by tracking and diagnosing more than 16 structural definitions and using a battery of novel evaluative methods.
Do standards exist for UI structural engineering?
As of this post, there are no official industry standards for assessing UI structure. Methodbrain has amassed a decade of research in UI structure through the lens of information architecture science. Our investigation of information behavior has resulted in internal standards that we use to deliver reliable UI engineering services.
What professional practices help to address UI structure?
UI structural engineering originates from the application of UI-based information architecture practices and information architecture science. Information architects have earned a reputation for their ability to design UI structures. 
In the absence of a specialist on the team, it is common for practitioners of UX design, interaction design, content strategy, and product management to rationalize the structure. However, their use of basic techniques provides much less traceability and manageability of the UI structure.
Can we call UI Engineering…Information Architecture?
The most popular concepts of information architecture are centered on how content is organized, labeled, and navigated. There are many methods and approaches to achieve these goals, which have now become common practice for UI and UX designers. However, this narrow generalization of information architecture as a practice has diluted the necessity of IA specialization for more complex circumstances.
UI structural engineering approaches these more complex circumstances by addressing systems of context, systems of behavior, systems of content, systems of interaction, and more. At this level of complexity, the study of information architecture shifts toward science and the contribution that information architecture science makes to improving human-digital interaction. I’ve posited in my own research that IA science contributes to improving the structural function of application user interfaces .
Overall, UI structural engineering is broader than common information architecture practices because UI engineering must consider more in-depth structural and operational behaviors that support application user interfaces in the most complex states.
Can we call it UI Engineering?
Yes, UI structural engineering can be called UI engineering. However, this may be confusing to someone who uses UI Engineering as an alternate term for UI design. Over the years, this has become less common. At Methodbrain, we add the word “structural” to reinforce the fundamental value proposition and limit confusion. However, the long-term goal is to promote “UI Engineering” as the preferred term over “UI Structural Engineering.”
 This is similar to Jared Spool’s definition of design as “the rendering of intent.”
 This perspective is based on the DSIA definition for information architecture as a work product.
 Davis, N. (2013). Transforming our conversation of information architecture with structure. Journal of the American Society for Information Science and Technology. https://asistdl.onlinelibrary.wiley.com/doi/full/10.1002/bult.2013.1720390510