New product development based on non-functional requirements in renewable energy industries using hesitant fuzzy QFD-DFX approach

Rapid changes in customer needs (CNs) and technology force businesses to develop new products to compete. Functional requirements (FRs) and non-functional requirements (NFRs) are created when CNs are correctly interpreted. FRs specify what the product must do, whereas NFRs specify how a system must behave. The study presents a comprehensive framework that helps product developers accurately and quickly extract the essential NFRs. This is because there is still no agreement in the requirements engineering community regarding which NFRs should be elicited for developing a system and how they should be applied and documented. Moreover, the majority of research in this area has either concentrated more on the field of software development or given more attention to applying FRs and less attention to NFRs. The presented framework applies the integrated approaches of QFD, DSM, and hesitant fuzzy sets (HFS). Design for eXcellence is also used to ensure that system quality attributes, such as NFRs, are considered during the development process. The framework was used to develop a solar power system, and the results indicated that the primary NFRs essential for system development are availability, reliability, maintainability, modularity, flexibility, and extensibility.