The Dynamics of Requirements and Product Concept Management A Product Modelling Approach
Product development is in many respects the process of identifying and envisaging needs and bringing those needs into life. To make it challenging, the competition forces companies to continuously reduce development and manufacturing cost while increasing customer satisfaction. As part of this process, large and complex development organisations, with numerous ongoing development projects and outsourced development activities, are faced with the challenge to continuously communicate purposes, goals, and requirements to all involved actors. Furthermore, reflecting on the product and collaboration complexity, it is obvious that concept work becomes more important in order to develop a purposeful requirements specification and well-balanced concept for the continuing project. Reflecting these challenges this research work, containing both descriptive and prescriptive elements, aim to bring forward knowledge and experiences regarding requirements management in practice, and to transform this understanding into better requirements and product models, involving documentation, elaboration, and communication of requirement and product descriptions, thus contributing to the development of better design tools.
The empirical elements of this research work have shown that the management of requirements in practice is interwoven in the general organisational structures and processes at the automotive manufacturer studied, and that the harmonisation of conflicting aims are a major challenge and opportunity. Contrary to prescriptions in many methodologies it is evident that requirements are changed, added, and reprioritised throughout projects, mainly due to conflicts, infeasibilities, changed pre-requisites, and the knowledge gained through the development work.
Prescriptively, this research work has developed a framework, based on the Theory of Domains, that relates requirements and design intentions to a constitutive product model letting requirements and design solutions co-evolve. More specifically, this research work has contributed to a product model that lets designers explore an envisaged product in a means-end space (from requirements to satisfying product descriptions) as well as a whole-part space (from complete product to individual components). Most importantly, this research work has argued for how functional representations can act as a framework to elaborate and structure requirements, because they give an abstract view on the design problem. Another empirical finding, central to this research work, is the importance to bring forward underlying rationale underlying requirements and product concepts in order to support communication, decision-making, and knowledge retrieval. Based on this insight a feature-based framework to represent design rationale has been introduced in the prescribed requirements and product concept model.
The findings presented in this thesis take to a large extent a design perspective on requirements management and concept development, but also incorporates elements from manufacturing engineering.
design theory and methodology