Heavy Machinery Documentation Viewer
I shipped the end-to-end redesign of Spogen.ai’s Documentation Viewer for heavy machinery, from concept to production.

Heavy Machinery Documentation Viewer
Spogen.ai helps teams create, manage, and use product documentation more intelligently. For this project, I redesigned its Documentation Viewer for heavy machinery.
The original HTML page made the manual available, but it did not make it usable in the field. I redesigned the experience around how people actually work with machinery: by task, visual context, and the relationships between parts and systems.
The goal was to make heavy machinery documentation easier to search, understand, and use in high-pressure work environments where users need fast and safe answers.
Solo Designer
I led the end-to-end design of the Documentation Viewer.
My work included:
Understanding the existing HTML manual and the Documentation Builder that generated it.
Conducting contextual inquiry with an internal stakeholder experienced in machinery documentation workflows.
Defining user needs for operators, maintenance technicians, and supervisors.
Creating information architecture, wireframes, UI designs, and an interactive prototype.
Running two rounds of usability testing and iterating based on observed behavior.
Designing reusable patterns that could extend to Spogen’s AI Assistant and Documentation Builder.

Outcome & Impact
What changed
5 of 5 usability tasks were completed successfully in the first round with two internal stakeholders.
The System Graph was identified by the CTO as valuable enough to extend to Spogen’s AI Assistant and Documentation Builder.
The procedure view was recognized for turning long manual content into clearer, task-based steps.
Role-based filters were removed after testing showed that use-case filters were clearer and faster.
Potential business impact
Faster time-to-answer for routine maintenance and troubleshooting.
Reduced reliance on support teams for basic documentation questions.
Safer execution of maintenance tasks through clearer procedures and visible safety context.
A reusable system-navigation pattern across Spogen’s documentation products.
What still needs validation
Field testing with operators and technicians using real machinery.
Measurement of search success, time-to-answer, support-ticket reduction, and procedure-completion accuracy.
Safety review of procedure order, warnings, and error-recovery paths with domain experts.

The Problem
The existing HTML page rendered the manual, but it was not designed for how field work happens.
Heavy machinery documentation is long, technical, and safety-critical. Users do not open it to read a chapter from beginning to end. They open it because they need to complete a task: inspect a machine, diagnose a fault, replace a part, or verify that maintenance was performed correctly.
The original experience treated all users and all tasks the same.
Six structural problems
Search lacked intent. Results showed only a title and chapter number, so users could not tell whether a result was a procedure, troubleshooting guide, safety warning, or part reference.
Navigation was chapter-first. The manual’s structure did not match how users thought about the machine or their current task.
Long pages created disorientation. With 11 chapters and hundreds of sections, users could lose their place after scrolling, searching, or following a deep link.
Image callouts obscured the image. Detail cards covered the very visual information users needed to understand.
Related content was disconnected. Parts, procedures, videos, warnings, and subsystems were separated across the manual.
Procedures were not execution-ready. Long text blocks made it harder to follow steps safely, especially when users were working near the machine.
Who uses it
User | Primary task | What they need |
|---|---|---|
Operator | Daily inspection and safe operation | Quick checks, warnings, and operating steps |
Maintenance technician | Diagnose, repair, and replace parts | Procedures, part context, tools, and related systems |
Supervisor | Verify work and compliance | Completed procedures, safety requirements, and audit context |
The Solution
Before: A single HTML manual treated operators, technicians, and supervisors the same way. Users had to search through 11 chapters and hundreds of sections to find one safe procedure.
After: A task-based Documentation Viewer that lets users search by intent, scan visually, follow procedures step by step, and explore the machine as a connected system.
Evidence: 5/5 first-round task success; System Graph adopted across two other products.
Challenges
The challenge was not only information density. It was designing for people using documentation under time pressure, in physically demanding environments, where an unclear step can create safety risk.

Design Process
Audit the existing experience
I audited the HTML Documentation Viewer and conducted a usability heuristic evaluation to identify navigation, search, hierarchy, and safety-related friction.Understand user needs
I created AI-assisted personas for operators, maintenance technicians, and supervisors to understand their goals, workflows, and documentation needs. I validated these needs through contextual inquiry with an internal stakeholder.Define the experience principles
I translated the findings into fast wayfinding, safe execution, system-based navigation, and progressive disclosure.Design one problem at a time
I addressed search context, navigation orientation, image callouts, procedure execution, and system relationships separately. I created wireframes and solved one UX problem at a time, using Claude and Codex to support research, wireframing, and code prototyping.Test and iterate
I tested the first prototype with two internal stakeholders and refined the design based on observed behavior.Design for reuse
In the second iteration, I also studied the Documentation Builder platform that generated the HTML page, and the AI Assistant experience. This helped me think beyond one viewer and design features that could be reused across products.




Identifying Design Principles
Before a single wireframe was drawn, four principles shaped every decision that followed.
Fast wayfinding
Find the right section quickly. Every feature reduces the number of steps between intent and content.
Keep users oriented
Whether users arrive through search, a deep link, or the sidebar, they should always know where they are and how to return.
Make safety impossible to miss
Warnings, required tools, and critical steps should remain visible during execution, not hidden inside long text.
Show the machine as a system
Reveal complexity only when needed. Overview first, detail on demand, from the sidebar to the System Graph nodes.
Reveal complexity gradually
Show the overview first. Let users open detail only when they need it.
Sketching & Iterating
After the first prototype, I tested the design with two internal stakeholders. Based on their feedback, I refined the navigation, filters, image callouts, and graph interactions.
In the second iteration, I also studied the Documentation Builder platform that generated the HTML page, and the AI Assistant experience. This helped me think beyond one viewer and design features that could be reused across products.
Design System
I created a lightweight design system to keep the viewer consistent and scalable.
It includes:
Typography and spacing scales.
Color and status styles for safety, warnings, and navigation states.
Cards, buttons, filters, tabs, breadcrumbs, and sidebar components.
Image-callout and procedure-step patterns.
System Graph node and connection styles.
I used Mobbin MCP as a reference tool to study established interface patterns. The final components were adapted to Spogen’s product context, content density, and safety-critical use case.

FINAL DESIGNS
Search by intent, not chapter
The challenge
Search returned titles and chapter numbers, but users could not tell whether a result was a repair procedure, troubleshooting guide, safety warning, or part reference.
Design decision
I added intent-based filter chips above search results:
Troubleshooting
Daily use
Repair
Maintenance
Parts
Safety
These filters reflect the reason someone opens documentation, not the way the manual is internally organized. Recent searches remain visible so users can return to a previous task without starting over.
Why it matters
Users can narrow by intent before clicking. A technician searching for “brake” can immediately narrow the results to a repair procedure or safety warning. This reduces guesswork and prevents users from opening irrelevant sections.

Home Page: List View + Gallery View
The challenge
A flat list of 11 chapters and hundreds of sub-sections made it difficult to scan or know where to stop. Some users navigate by structure; others remember content by its visual layout or imagery.
Design decision
Two switchable views serve two mental models.
List view: It uses progressive disclosure, chapters collapsed by default, expanded on demand, so users see only what's relevant to their current task, not the full weight of the manual.
Gallery view: It organises pages within each chapter as a horizontal scroll, letting users quickly scan page thumbnails chapter by chapter without leaving the view.
Why it matters
Progressive disclosure in List view reduces cognitive load without hiding content, the structure is always visible, but the detail only appears when the user asks for it. Horizontal scroll in Gallery view turns chapter browsing into a spatial experience, matching how visual thinkers locate content by memory of layout and image.

Sidebar: List View + Gallery View
Persistent Breadcrumb
The challenge
In an 11-chapter document, users could lose orientation after scrolling, searching, or opening a deep link. The sidebar’s active state also broke when a chapter was collapsed.
Design decision
I added a persistent breadcrumb in the main content area. It remains visible regardless of sidebar state, scroll position, or entry point.
Why it matters
The breadcrumb acts as a location anchor. Users can always see the chapter and section they are in, then move upward without restarting their search.
Navigation that matches two mental models Sidebar: List View + Gallery View
The challenge
The original sidebar offered one text-based navigation model. Users who located content visually had no way to browse by image, and the active state disappeared when a chapter was collapsed.
Design decision
Two switchable sidebar view modes, inspired by the Google Chrome PDF viewer. I designed two sidebar modes:
List view: A structured table of contents with both parent chapter and active sub-section highlighted.
Gallery view: Page thumbnails labelled by section number for visual scanning.
The active state remains visible in both modes, even when a chapter is collapsed.
Why it matters
Users always retain orientation. The list serves structural navigation; the gallery supports visual recognition. Both prevent the “I am lost” moment.

Image Callout Side Panel
The challenge
Detail cards covered the image they annotated. Users could not easily compare callouts or understand how components related to the wider system.
Design decision
I moved callout details into a structured side panel. The image remains visible, while callouts appear as a scannable table with item numbers, descriptions, zoom controls, and a link to the System Graph.
Why it matters
Users can inspect a component without losing visual context. They can also compare callouts and move from a part to its related system or procedure.
When a user selects a callout, the corresponding part is highlighted on the image. This creates a clear connection between the diagram, the description, and the next action.

System Graph
The challenge
Users do not experience heavy machinery as a sequence of chapters. They experience it as connected systems: a hydraulic fault may affect multiple components; a repair may require understanding related subsystems; a part may connect to several procedures and videos.
The original documentation had no way to explore these relationships.
Design decision
I designed an interactive System Graph. The graph does not replace the manual. It provides a second entry point for users who think in terms of systems, faults, and component relationships.
The default view shows a simplified machine-system overview.
Selecting a node reveals its description, connected subsystems, related procedures, and videos.
Users can zoom, expand, collapse, and reset the view.
Related content is accessible without leaving the graph.
Why it matters
The System Graph helps users move from a part or fault to the information needed to act safely. It also became a reusable Spogen pattern: the CTO identified its value for the AI Assistant and Documentation Builder.
Edge Cases
A node with no related procedure shows: “No procedure available for this subsystem.”
A dense graph defaults to a simplified overview, with expansion on demand.
Selecting a warning node leads directly to the relevant safety guidance.
A “Reset view” control restores orientation after exploration.

Procedure Slideshow
The challenge
Maintenance procedures can be long, technical, and safety-critical. Users need to read a complete step, understand required tools and warnings, and know where they are in the sequence. The original format presented this as long-form manual content.
Design decision
I redesigned procedures as a step-by-step slideshow.
Each step is presented separately, with room for long content and vertical scrolling.
Navigation arrows sit on the sides, outside the content flow.
A persistent step indicator shows “Step 3 of 12.”
Required tools, parts, PPE, and estimated time appear before the procedure begins.
Safety warnings remain visible while the user scrolls.
Users can mark steps complete and return to the related system or part.
Why it matters
The procedure becomes something a technician can follow while working, rather than a long document they must interpret. Side navigation avoids competing with scrolling, while persistent context reduces the chance of skipping a critical step.

Learnings
Use-case filters work better than role filters when roles overlap.
I initially designed filters for both roles and use cases. Testing showed that role names created confusion because users saw themselves in more than one role. Use cases such as repair, maintenance, and troubleshooting—were clearer and faster.Shadowing changes what you design.
Reading about users is different from watching them work. The System Graph came from observing how an internal stakeholder moved between parts, procedures, and related content—not from an assumption made during initial research.Solve one problem at a time.
Designing each UX failure separately kept decisions traceable and made usability findings easier to interpret.A strong interaction needs operational boundaries.
The System Graph was compelling, but it also needed rules for empty states, dense systems, reset behavior, and missing content. A feature is not finished when it works; it is finished when it fails safely and clearly.

Key Design Decisions
The most important shift was moving from a document-based experience to a task- and system-based experience.
The original viewer answered, “Where is this information in the manual?” The redesigned viewer answers, “What am I trying to do, what system am I working with, and what should I do next?”
If I continued the project, I would:
Test with operators and technicians in real workshop conditions.
Add offline access and low-connectivity states.
Validate procedure safety, sequencing, and warnings with domain experts.
Add grounded AI search that answers questions with links to the exact procedure, warning, part, and video.
Measure time-to-answer, search success, procedure completion, and support-ticket reduction.