Scrum teams aim to deliver products productively with highest possible value and quality, so they try to deliver high priority and high value product backlog items in earlier sprints. Making size estimation of product backlog items correctly is one of the most prominent factors for effective sprint planning. Retrospective meetings are an opportunity for teams to improve product quality, their productivity, and estimation capability. Enhancing in those areas requires empiricism as agility requires; hence, measureable indicators should be inspected and adapted at regular intervals.In this study, we assessed how and what kind of historical data is required to be collected for monitoring, and how statistical analysis can be investigated for inspection and adaptation in retrospective meetings. We experimented that statistics of "Correlation between Story Point and Actual Effort" and "Consistency of Relative Estimation" were convenient for inspection and adaptation of estimation capability of teams. Past retrospective meetings also showed that statistics of "Team's Actual Effort on Product," "Team Velocity," "Actual Effort for One Story Point," "Innovation Rate," and "Velocity vs Unplanned Effort Rate" were helpful to control and increase the productivity of teams. "Actual Effort Rate of Quality Activities" and "Subcomponent Defect Density" statistical results helped to enhance product quality. KEYWORDS process improvement, product quality, productivity, Scrum, sprint retrospective, statistical analysis 1 | INTRODUCTION Agile development methodologies increase its popularity in developing software as requirements and solutions evolve based on incremental and iterative development through collaboration between cross-functional teams. Scrum, which is used widely, is a subset of Agile framework for completing complex software projects considering adaptation in roles, artifacts and time boxes. Implementation of Scrum in projects showed that it significantly increases productivity and reduces time in comparison to classic life cycles such as waterfall or incremental iterative as well as organizations benefits to cope changing requirements and work products and produce a quality product that satisfy business goals.Scrum is flexible and often adapted in different contexts in organizational implementation. A study 1 investigates the reason of the changes in Scrum in practice within different organizations. Results show that the least variations are observed in sprint length, size of team, and requirement engineering process, while the most varied ones are in roles, relative estimations, and quality events. As quality events include measuring, monitoring, and evaluating the process for improvement opportunities, 2,3 implementing that Agile methodology has a major importance in determination to help the team better understand their development process in terms of enhancing ability to manage changing priorities, improving visibility of project, and improving the team's morale. 4 This is possible by measuring the progress as the t...