## 5 Conclusions
### Limitations  
Even though this research may contribute to the use of occupancy sensing in practice, there are some limitations to this research. The use of interviews proved to be an excellent way to generate the right information, but it would have been better for the research if a second data collection method had been added. The scope of the research was clear, but it turns out that the subject is more significant than previously expected. By looking at the position of FM, the scope was enlarged and became more than just the added value of occupancy sensing. Care had to be taken during the research that the study did not become too broad and that the focus remained on occupancy sensing.  
The limitation of the sample size was that there was only one interview with a non-user. Better insight into the disadvantages of occupancy sensing would have been obtained if more interviews with organisations that consciously choose not to use occupancy sensing were conducted. This would complement the insight into the current market. Besides, the quality of the sensors and the type of sensors used by organisations were not discussed in depth during the interviews. However, this was an essential factor that emerged from the literature review. In addition, the data maturity of the organisations was not questioned. It would also have been better for the study if there had been a discussion with an organisation that was ahead in the field of smart features and where the entire office was smart. It would also have been an addition if the researchers could visit the locations to get a good picture of the current situations and the added value. However, this was not possible in connection with the COVID-19 pandemic.  
Another limitation of the study was that the native language of the researchers is Dutch, and the interviews were also conducted in Dutch. After the interviews, the results were translated into English. It is possible that with this translation, information was lost or was interpreted differently. To limit this, it was all checked by someone whose native language is English. However, there may be some difference in the information.  
To ensure reliability, respondents were interviewed in a location that was comfortable for them. Because of the COVID-19 pandemic, the respondents were interviewed mainly digitally from their homes. Additionally, to ensure reliability, the topic list was sent to the respondents beforehand, and they were immediately asked whether all topics were clear. In this way, the respondents knew in advance what the topics would be, and this could also be prepared by the respondents. The limitation of qualitative research and interviews remains that the results are based on the interpretations of the researchers. To limit this, quotes from the transcripts were used instead of the interpretations of the researchers from the interviews themselves.  
The validity could be improved, many of the same answers were given but this could be generalised. Therefore, the results would have to be tested again. The validity was threatened because the research group was a limited sample of the total population regarding occupancy sensing. The respondents work for a limited number of types of organisations. The interviews were anonymous, but the type of organisations they work for did influence the results. Due to a lack of time, respondents from different organisations were not actively searched for, but to be able to generalise, this would have been better.  
In the end, the researchers had to deal with different people who had different opinions. The added value of facility management remains an intangible concept, and many factors influence it. That is why there is still plenty more research to be done on this subject. The recommendations for further research from the researchers are described in Section 6.