Good UX is still important even when users are forced to use your software
How can you track your impact when you’re designing internal apps?
“The problem is, I’m designing an internal tool, so I don’t know what impact I have.” A Senior Designer told me. That’s often one of the most common complaints I hear in my course.
In 2025, the most critical skill designers need is the ability to translate their design work into business impact.
Businesses aren’t paying for pretty pixels when budgets are tight: designers are asked to draw clear connections to justify their value.
“At Target, everything needs to connect to loyalty metrics and customer lifetime value. When I present design decisions, I always start with how this impacts our business KPIs, then explain the design rationale.” — Twisha Shah-Brandenburg, Design Leader at Target
But what happens when you don’t have a direct way to track impact, like with B2B (or Internal) applications?
Then, you need to learn about CASTLE.
B2B Design: When Users Don’t Have a Choice
One of the most challenging aspects of designing for internal applications is that users don’t have a choice.
Think about where you work. Are you forced to use specific tools, either for meetings (Zoom/Teams), Design (Figma), or more?
That’s often because your CEO will purchase software for employees to use, whether they like it or not.
Whether it’s doctors using whatever hospital administrators buy, or office workers worldwide, the question remains:
What impact does design have when users are forced to use the software?
After all, unhappy users in B2C environments might leave your site or switch to a competitor. However, if your company is only paying for one piece of software, employees might complain about it, but be forced to use it anyway.
This is why the Nielsen Norman Group developed CASTLE, as a complementary framework to traditional metric tracking.
CASTLE, or what affects internal applications
CASTLE is a framework by Page Laubheimer (of N/Ng) explicitly designed for internal applications to showcase how UX affects internal applications.
It stands for:
Cognitive Load: Ensuring software is easy to understand and doesn’t overwhelm users with information
Advanced Feature Usage: Encouraging users to utilize advanced features that enhance productivity
Satisfaction: Measuring how pleased users are (or how much they tolerate) the software
Task Efficiency: Determining how quickly and effectively users complete tasks
Learnability: Assessing how easy it is for new users to learn and become proficient
Errors: Monitoring the frequency and severity of user mistakes and system errors
It tracks and measures the internal user experience while also helping to translate its impact in a way that businesses can understand.
Why does this matter? Because unhappy users affect what businesses care about in other ways.
For example, if users avoid advanced features like an AI-powered chatbot your company wants to roll out, that becomes a significant business problem.
Here’s how to use it.
Step 1: Align with Internal Business Goals
This is actually where many designers struggle the most. You don’t need to create business goals from scratch.
Your team likely already has them in place, such as measuring project changes, contract renewals, and similar metrics. All you need to do is align your efforts around them.
Most of the time, the primary problem you’ll face is with Employee productivity and retention.
When internal software is poorly designed, users:
Struggle to understand how to complete tasks(due to cognitive load)
Will only do the bare minimum (which affects advanced feature usage)
Are more likely to be unhappy (and quit their job)
This translates directly to business impact, like:
Employees are taking much longer to complete tasks
Users not using advanced software, which means the company isn’t getting ROI on expensive software licenses.
If the system is complex to learn, onboarding becomes more expensive.
“We redesigned our internal CRM and initially focused on ‘user satisfaction’ metrics. But when I translated that to ‘reduced training time from 3 weeks to 1 week,’ suddenly leadership cared. That’s a $50K savings per new sales hire.”-Director of UX
The key is connecting CASTLE metrics to what your stakeholders already measure.
Step 2: Choose CASTLE Metrics Based on Primary Impact
Not every CASTLE metric will matter to your specific situation. Here’s how to prioritize:
If your business cares about operational efficiency, Focus on Task Efficiency and Errors
Translate this into specific business metrics like “Time to complete key workflows” or “Error Frequency.” This applies to repetitive tasks like:
Processing 100 applications daily
Executing 100 stock trades per day
Quickly accessing patient Electronic Medical Records
If you’re launching new features/tools, Focus on Advanced Feature Usage and Learnability
When users aren’t adopting new features, focus on feature adoption and potential impact on contract renewals. Nobody wants to pay for unused services. Examples include:
Dashboards that nobody uses
Bulk uploads/imports that people ignore
Expensive training costs because people can’t learn independently
If you’re dealing with change aversion, Focus on Satisfaction and Cognitive Load
Cognitive load and satisfaction directly correlate with customer support tickets. When users are unsure about how to do something or find it too complex, they contact support. Examples include:
Hundreds of support tickets about “Installing this program”
Support calls to walk users through specific tasks
Forum complaints about common, specific problems
Step 3: Make It Measurable (Even Without Analytics)
Internal applications often lack data tracking, but you can still gather meaningful data in several ways.
Task Efficiency: Time employees with a stopwatch during key workflows during user testing
Errors: Count support tickets or help desk requests related to your application
Satisfaction: Send brief monthly pulse surveys (2–3 questions maximum)
Advanced Feature Usage: Check admin dashboards or ask IT for usage reports
The Coffee Route Approach
Another alternative that I heard many designers mention is going “the coffee route” for getting metrics. Build relationships with:
IT administrators who have access logs
Customer support teams that handle user complaints
Training teams who track onboarding times
Department heads who see productivity impacts
Ask about those metrics, and see if you’re able to spell out the difference you’re making with internal applications.
2025: The Year of Design Efficiency
In 2025’s “year of efficiency,” every design decision must justify its cost. Internal applications are often seen as “necessary evils” rather than competitive advantages.
But when you can demonstrate clear productivity gains, error reductions, and cost savings through CASTLE metrics, design becomes indispensable.
Whether you’re designing for doctors using Electronic Medical Records, field office workers using outdated tools, or construction companies collaborating with partners, you can still showcase design’s business impact.
You may need to lean into CASTLE, as your users often don’t have a choice.
Want to learn how to use CASTLE? I teach that in my course.
Kai Wong is a Senior Product Designer and Data and Design newsletter Author. He teaches a course, Data Informed Design: How to Show The Strategic Impact of Design Work, which helps designers communicate their value and get buy-in for ideas.