Mass customisation combines the flexibility of custom-made products with the efficiency of mass production, addressing individualisation and sustainability across various industries. This trend, driven by digital advancements and adaptable manufacturing, faces challenges in the widespread adoption of product configurators. These tools, while enabling users to be a part of the product development process, often have limitations such as predefined options that may not fully satisfy customisation needs and complexity in aligning user requirements with the final product.

As such, this research seeks to answer the question: How might we improve the digital customisation experience to support a more user-centred experience, ultimately resulting in products that users find satisfying and cherish, thereby promoting their long-term use?

This thesis presents an investigation into the user experience during the digital product customisation process, focusing on case studies in the Fashion Industry. The research adopted the Design Research Methodology (DRM) framework, employing a mixed methods approach across three interlinked studies.

The research offers new insights into the role of mental imagery in digital product configuration and its impact on customisation efficacy. It proposes a new construct for understanding the relationship between cognitive effort, mental imagery, and the effectiveness of digital product customisation processes. This approach emphasises the need for configurator designs that support multiple types of mental imagery.

By enhancing user satisfaction and bridging the gap between digital decisions and real-world outcomes, this research supports users in becoming co-designers and enables more effective mass customisation in digital manufacturing systems. This research sets a promising direction for improving digital product customisation by addressing user experience challenges and developing products that align closely with user needs and preferences. The goal is to create customised items that are more valued, used longer, and ultimately contribute to sustainable production and consumption practices.