The extended next release problem. Generic Formulation of the Requirements Selection Problem
Isabel del Aguila, Jose del Sagrado, Alfonso Bosch
TL;DR
This paper introduces extNRP, an open, generic formulation that generalizes the Next Release Problem to accommodate unlimited objectives and constraints driven by heterogeneous requirements attributes and interactions. It defines a formal data model for requirements, interactions, and multivalued stakeholder-based attributes, and presents a three-phase usage process: specify objectives/constraints, compute Pareto-optimal solutions, and analyze/choose a release plan using quality indicators. Through six instantiated NRPs (including Motorola, classic NRPs with interactions, MSLite, and Theme-based planning), extNRP demonstrates versatility in handling refinement, combination, exclusion, and value interactions, while enabling what-if analyses and decision support with interpretable indicators. The framework aims to unify prior approaches, cover a broad range of practical scenarios, and support future extensions as software engineering practices evolve. The practical impact lies in enabling organizations to tailor release planning to their data, stakeholder structure, and policy constraints while maintaining a coherent optimization-and-analysis workflow.
Abstract
Due to the limited amount of resources available for the next release of the current product under development not all stakeholders requests can be included in the next product to deliver. This optimization problem, known as the Next Release Problem (NRP), has customers satisfaction and development costs as the basic optimization objectives, and has been the subject of many research works. However, there are additional issues that deserve to be considered and included in the definition of the NRP, such as supplementary optimization objectives including the elicited properties about the requirements, or the analysis of the non-dominated solution sets found to decide which solution is preferred. This paper presents a generic formulation for this problem that allows the management of the currently agreed properties and relationships between requirements. It provides an open formulation that is capable of growing as the scope of the NRP grows. We specify how our proposal can be used in software product projects when requirements selection has to be performed. We also describe how our formulation has been instantiated to cover previous solving approaches to this problem, using six case studies to demonstrate the successful customization of the generic formulation.