Chosen Method for Requirements Change Management. As part of WP6 and IoT-A, a software development method combining aspects from agile principles and the Spiral method was chosen. The waterfall method's rigidity makes it inappropriate for IoT-A; during the project requirements will evolve, and new ones added to the collection. This could be caused by a changing research situation in the area of Internet of Things, which requires the flexible adaption of the project. With regard to the requirements change process the following general considerations were made, which are covered by agile principles and the spiral model (see Figure 3): • All requirements are stored in a set of lists in the software tool Requirements Aid (Reqaid). The entire requirements list will be reviewed at regular intervals. A corresponding functional time interval will be defined within the project. As per the agile methods, any new requirements which arise from the stakeholders can be added and implemented quickly - an advantage to meet the needs of stakeholders. • The requirements list remains constant over a certain time period, in which development takes place. For instance, this "requirements freeze" is needed for the development process of the Future Internet Layer of WP 2. In this way a stable development process can be realized for the involved developers. • Then, at regular intervals, a review and a final validation of the requirements list is needed including internal and external project stakeholders. Depending on these results the priority of certain requirements can be adapted and thus influence the remaining process. Therefore both requirements and the development process are iteratively updated, as per the spiral model. This process ensures that all features are primarily developed, that are most beneficial for the solution. Requirements are defined on the internal and external stakeholder side during the project and iteratively updated over the design cycle.
