Introducing requirements engineering into product development : towards systematic user requirements definition

Without knowing the requirements of customers and users, it is difficult to build the right product. Although requirements engineering (RE) is considered a critical activity in product development, the state of RE practices seems to be immature in many organizations. For several years, researchers have tried to understand why so many companies have informal RE processes and why it is so difficult to introduce RE technology into mainstream practice. This thesis investigates how RE can be introduced into organizations that develop market-driven products. The results are based on the experiences gathered from four Finnish organizations that considered it essential to improve their product development processes by investing in RE. To gain a deep understanding of RE process improvement in real product development contexts, we conducted four longitudinal case studies using an action research approach. One of our main findings is that introducing RE into product development appears to involve a cultural change. By this we mean that development personnel need to adopt a new way of thinking and working when defining requirements systematically from the customers' and users' points of view. Furthermore, this cultural change involves such human factors as beliefs, attitudes, motivation, and commitment of development engineers and managers. One way of supporting the cultural change is to define a simple RE process model that links business goals to technical requirements via user needs and user requirements. The purpose of the process model is to give an overview of RE, support communication by providing common terminology, and emphasize the importance of systematic user requirements definition. On the basis of the lessons learned from the four case studies, we also recommend a set of RE practices that support the systematic definition of user requirements. Furthermore, the thesis provides a model of factors that affect organization-wide implementation of RE practices and describes challenges organizations may face when introducing RE into product development. The main conclusion drawn from this work is that changing the perspective from technical requirements to user requirements can be difficult for product development personnel. Furthermore, it can take several years for the cultural change towards systematic user requirements definition to spread throughout the whole product development organization. However, the experiences from the case studies show that the organization-wide adoption of RE practices can be enhanced by offering Just-in-Time training and an RE expert's assistance for development teams when they are defining user requirements for the first time.reviewe