Choosing Between a Design System and a UI Kit

Inconsistent screens do not automatically justify building a comprehensive design system. First identify the source of inconsistency. Are reusable components missing? Do teams lack shared interaction rules? Is ownership of design decisions unclear? The need should determine the scope.

A UI kit can collect visual components for designers to reuse. A design system also addresses shared patterns, usage guidance and how the system is maintained. Nielsen Norman Group describes design systems in terms of standards supported by reusable components and patterns.[1]

Distinguish a library from an operating model

Having a Figma library does not mean the implemented components behave consistently. IBM Carbon, for example, includes working code, design tools, resources and guidance.[2] That does not mean every organisation needs a system of the same scale. It shows why the scope can extend beyond visual files.

For a single team whose product interactions are still changing rapidly, a focused component library may be the better starting point. When several teams repeatedly solve the same problems in different ways, shared decisions and maintenance become more important.

Evaluate concrete signs of need

This is not a maturity score. Different products in the same organisation may need different approaches. The number of components in a library does not establish whether a system is useful.

Start with one recurring journey

In a hypothetical admin product, an initial scope might cover form fields, validation, buttons and notifications. Examine how these elements work together in a real task. When defining colour, typography and spacing variables, agree their relationship to the implementation.

Document more than a component's default appearance. Include relevant states, content constraints, keyboard behaviour and situations where it should not be used. Accessibility work extends beyond choosing a colour palette; it needs attention during implementation and testing too.

Include maintenance in the scope

Agree how components are proposed, who approves changes and how older versions are retired. Saying “everyone will use it” does not establish a working contribution process. Create a way to hear product teams' needs and record justified exceptions.

Evaluate more than library usage counts. Examine design and code alignment in important journeys, duplicated solutions and problems during upgrades. A design system should support product work rather than become a separate objective that is considered finished once the library is published.

Frequently asked questions

Is an existing component library enough

It may address part of the need. You still need to assess fit with your brand, content and product behaviours. Review its maintenance and accessibility separately.

Can we start with a UI kit and expand later

Yes. Extending the scope as recurring needs and stable patterns emerge is a practical approach. You do not need to anticipate every future component.

What should we prepare for an initial discussion

Collect examples of inconsistency, repeated components and differences between design and code. Explore VOYA UI UX design services to discuss an appropriate starting scope.

Sources

1. Nielsen Norman Group Design Systems 101
2. IBM Carbon About Carbon