This Bachelor Thesis focused on one of the divisions of the PSI, the energy and environment department. The diverse composition of stakeholders, high workforce turnover and the growing international presence at PSI makes communicating especially important. Knowing the target and being able to communicate group-specifically to their needs as well as regularity and the required depth is critical in ensuring an efficient flow of information. This traditional approach to communication has caused inefficiencies, misunderstandings, and further challenges yet to be explored through our research.

For this thesis the Oltner model was used, and a stakeholder analysis was conducted. Then, problem interviews were conducted with employees from different positions and laboratories to identify issues and needs concerning internal communication. Afterwards, assumptions were derived from the interviews and a quantitative survey was conducted. Then, the quantitative survey findings were compared to the developed assumptions and compared to past research in the field. Finally, a communication concept based on the preceding discussion and past literature research was developed.

All in all, this thesis provides further value due to its rich, representative, and comprehensive data collection that is made available to the client, serving as a basis for further analysis since the findings give more value than the scope that was agreed on with the client and more than is discussed and used for the concept in the end. By acknowledging the proposed recommendations, organisations, hr practitioners, and researchers get an overview of internal communication theories as well as valuable practical ideas for their work. For other organizations and the client, adequate communication is especially vital for achieving their long-term goals and short-term objectives. As change is a popular phenomenon nowadays, for example caused by globalization, environmental degradation, or technological development, organizations must improve their change management procedures, like internal communication, to be able to respond to these changes. Thus, this thesis helps the client and other organizations to enhance their resilience and responsiveness to change through addressing these internal communication issues and to strengthen their change management framework overall.