Factors influencing user story estimations: an industrial interview and a conceptual model

A proper estimation of time in user stories is a crucial task for both the IT team as well as for the customer, especially in agile projects. Although agile practices offer a lot of flexibility and promote a culture of continuous change, there are always clearly de need timeboxed periods where an IT company has to commit to delivering working soft-ware. Estimating time of user story implementation provides clarity and the opportunity to control the project by the management, yet at the same time, it can increase pressure on software developers. Thus, incorrectly estimated user stories may lead to quality problems including system malfunction, technical debt, and general user experience issues. The paper describes user story characteristics, reasons of user story estimation inaccuracy as well as a model of their potential impact on post-release defects in large IT software ventures, all derived from the conducted interview with practitioners in Capgemini software development company.