A company operating safety-critical manufacturing sites depends on a reliable alarm system, including protection for employees working alone. The current system, based on outdated devices, is nearing the end of its life cycle, is complex to administer, and its vendor support contract is ending. A modern, smartphone-based replacement was needed, but the requirements for such a system, and which vendor could best fulfil them, were unclear.

Requirements were elicited through interviews with internal stakeholders, a literature analysis of legal and safety guidelines, and a workshop, resulting in documented functional, non-functional requirements and use cases with full traceability. Two shortlisted solutions, Solution A and Solution B, were configured and tested against defined test cases in a proof of concept, and evaluated by future users via a questionnaire based on the Technology Acceptance Model.

The proof of concept showed that the solutions fulfil the large majority of the company's requirements. Solution A achieved the higher fulfilment rate, was consistently rated higher by users across usability, functionality, availability and acceptance, and scored higher in every criterion of a weighted decision matrix combining test results, user feedback and business assessment. Solution A is therefore recommended as the replacement for the current alarm system. Beyond the recommendation, the company gains a structured, reusable requirements catalogue and a documented, traceable evaluation method for future technology decisions. The thesis also highlights that technology alone does not ensure worker safety: training, up-to-date processes and regular testing remain essential.