What defines the system boundary in requirements engineering?

The correct answer highlights that the system boundary in requirements engineering is primarily defined by the aspects that need to be developed. This includes identifying which features, functions, and components are within the scope of the new system and what will be addressed in the requirements. Understanding the aspects for development establishes clarity around what the project aims to accomplish, which is crucial for effective requirements gathering and stakeholder communication.

Identifying the areas that require development allows teams to distinguish between the elements they need to focus on and those that are outside the project's scope, ultimately guiding the design and implementation processes. This focused approach is key in managing project resources and ensuring the final system meets the intended objectives.

In this context, aspects that are irrelevant to the system refer to external factors that do not pertain to the system's functionalities and can lead to confusion if considered during the development phase. The interfaces with legacy systems signify interactions with existing systems but do not define the system boundary by themselves. Although the perspective of end-users is valuable for gathering requirements, it does not specifically delineate the limits of the system; instead, it encompasses how users interact with the system which happens within that boundary.