Osoitetietojen laatutarpeet ja laadunhallinta : kehitettävän valtakunnallisen osoitetietojärjestelmän laadunhallinnan soveltuvuus tiedon käyttäjien tarpeisiin

High-quality address data is an essential part of a functioning society and its services. However, shortcomings have been identified in the quality of national address data that can, at worst, slow access to vital help in an emergency. Partly for this reason, National Land Survey of Finland (NLS) is developing a new national address information system (OTJ), which in the coming years will serve as the main database for Finland’s national address data. The OTJ's quality management methods are still under development. Currently, the incoming address data of the OTJ is planned to pass through a quality control service called Laatuvahti, which takes care of logical consistency of the incoming data by using quality rules. Preliminary quality rules of address data have been designed for the Laatuvahti service. However, the adequacy of the quality rules and the functionalities of Laatuvahti service to the quality management of address data has not yet been studied extensively. It has also not been clarified how well the quality management methods fit the needs of the users of the address data. In this master’s thesis the quality needs of significant address data users are discovered, the suitability of the OTJ's current quality management methods to the quality needs are examined, and it is determined how the quality management methods should be developed in the future. In addition, the quality needs are used in determining what does quality in address data mean. The address data users’ experiences on the quality of the address data were investigated through expert interviews. A total of seven interviews were conducted. The interviewees were selected to represent socially significant users of address data that use the data for different purposes. Interviewees were the Emergency Response Center Agency, the safety and rescue authorities, a navigation company, a telecommunications company, an energy company, a transport company and the Statistics Finland. The suitability of the OTJ's quality management methods was assessed by comparing the users’ quality needs with the existing address data quality rules and the functionalities and possibilities of Laatuvahti service. The suitability of Laatuvahti for quality needs was further verified by a service expert (from NLS). Most of the quality needs that the address data users raised in the interviews were related to thematic correctness of the address data (i.e. the correctness of the address name and number), positional accuracy and ensuring completeness and currency of the data. In addition, some of the needs were related to the address data structure, uniqueness and methods of reporting the quality level of address data. Based on the quality needs, the quality of address data can be defined simply to mean that the address data points and directs accurately to the intended location based on both its location information and the address name and number spelling. The results suggest that the OTJ's quality rules and the functionalities of Laatuvahti service only partially meets the needs of the users. The quality management methods are not suitable enough for managing the completeness and currency of the data. Some good efforts had been made to ensure thematic correctness through the quality rules, but the methods could be developed further. Positional accuracy was poorly ensured by the quality rules, but the methods could be developed to ensure the accuracy of location information better in relation to the user needs. In addition, the uniqueness of the address could also be ensured in a more versatile way. According to the results, new quality checks should be developed for the OTJ's quality management to ensure, among other things, the positional accuracy and the uniqueness of the address. In addition, recommendations for the structure and content of address names and numbers should be clarified and the quality of reference datasets used in the quality control should be ensured. In the future, it should also be clarified how the completeness and currency of address data can be monitored and should the quality results be reported in a feature level with some sort of a quality indicator value.