This thesis was made for the recycling center. The thesis had two objectives. First to examine, how much material was coming in and the hourly and daily cycles of this. Second part of thesis is the process analysis about recycling center’s procedures and improving those. The theoretical part of the thesis is focused on the Six Sigma and DMAIC processes. It is based on literature and publishing on Six Sigma. The research method used here was a quantitative Six Sigma study. Half of the research materials came from the client and the rest of the materials were collected by using DMAIC process. This research showed that erroneously returned material caused extra work and thereby the efficiency of processes is significantly weakened. Based on the results of the analysis, new process specific recommendations and instructions are provided on how to send the material back to the recycling center.