Abstract The practices proposed in agile methods to speed up software development, although they are beneficial to the organization, can affect the way in which requirements engineering activities are conducted as these practices are not explicit. These activities, when not carried out properly, can result in poorly understood, omitted and poorly specified requirements, leading to requirements debt and can compromise other stages of software development. However, requirements debts are little explored and, on many occasions, are unknown, not monitored or managed efficiently, which causes high maintenance costs over time. The objective of this article is to propose an Ontology focused on requirements debt in the agile context. The research was conducted through an investigation of the state of practice supported by \textit{grounded theory}, unifying the result with information obtained in two systematic studies of the literature: a systematic mapping of the literature that consists of identifying the causes, consequences and practices aimed at debts of requirements and a tertiary study focused on debt management, supporting the knowledge obtained about requirements debt and serving as input for the construction of an ontology, called “OntoReD”.

Background: Agile development was an important initiative that changed the traditional way of developing software into an agile development process.Action is more important than the process in the agile world, and requirements and documentation do more harm than good.However, when developing requirement engineering activities inadequately, they motivate the emergence of problems that directly affect the development, which can incur requirements debt.Aim: This study investigates the causes of requirements debt that incur requirements debt and actions that can minimize and or avoid them inside the context of agile software development.Method: To fulfill the objective, we performed qualitative research, supported by data analysis suggested by Grounded Theory, with 19 subjects in 13 agile organizations at a national and international level in different segments.Results: At the end of this study, we proposed a theoretical model containing the requirements debt causes and their effects and practices that might mitigate them, and the relation between these three factors.