Projectra : Designing a Digital Construction Logbook for Multiple User Roles: An Iterative Evaluation Using Heuristic Evaluation and Usability Testing

Sammanfattning

This study investigates how the usability of Projectra, a digital logbook system for construction projects, can be improved through an iterative design process that combines heuristic evaluation and usability testing. The aim is to analyse how these methods can be used together to develop a user-friendly interface that supports multiple user roles within the construction industry. The study is guided by two research questions: how the iterative combination of heuristic evaluation and usability testing affects usability, and how different user groups perceive and prioritise usability aspects. The design and evaluation process followed Nielsen’s Usability Engineering Life Cycle and was conducted across three iterations using low-, mid-, and high-fidelity prototypes. Each iteration included either user testing and heuristic evaluation, or both, which enabled continuous identification of usability issues and contributed to design decisions. Participants included construction workers as well as UX and construction domain experts, providing both practical and analytical perspectives on the interface design. The results show that the core concept of Projectra was easy to understand already in the early stages; however, low-fidelity prototypes revealed several structural and conceptual issues, such as unclear terminology, insufficient navigation support, and limited visibility of system status. Through iterative refinements, these issues were gradually reduced, and the high-fidelity prototype demonstrated high usability, clear interaction logic, and support for realistic workflows. Most identified issues could be mapped to Nielsen’s usability heuristics, indicating that the framework was relevant but required empirical validation to be applied correctly in practice. The study demonstrates that heuristic evaluation and usability testing function most effectively as complementary methods. Heuristics provided analytical structure and early guidance, while usability testing revealed how design decisions performed in actual use. Differences between UX experts and construction domain experts contributed to a more nuanced application of the heuristics and ensured that the interface was adapted to construction-specific work processes. In conclusion, the study shows that iterative usability evaluation is essential for developing digital tools that are both technically well-founded and practically usable. The findings contribute insights into how user-centred design can be applied within the construction industry and are also relevant to other domains characterised by complex workflows and multiple user roles.