Indah, Novia Handayani Putri2021-08-242021-08-242020-10wahyu sari yenihttps://repository.unri.ac.id/handle/123456789/10133Riau University Library has a number of visitors that vary each year. The uncertainty number of visitors within a year as well as the lack of infrastructure in Riau University Library, therefore a system to predict number of visitors each year is required to improve its facilities and services. This thesis describes the process of predicting the number of visitors to the Library of Riau University using the Decomposition Method. The research was conducted by analyzing the data requirements, collecting data and predicting the decomposition method. In the decomposition method, there are four calculation stages in the decomposition method, namely finding the value of the Trend, Seasonal Index, and Cyclic Variation, and the error value. In the system design stage, there are three diagrams used, namely Use Case, Class Diagram, and Activity Diagram. Manual calculations and system testing are carried out to produce the same output, so that the resulting predictions can be said to be valid.enDecomposition MethodPrediction of the Number of VisitorsInformation SystemsArticle