What is the function of data flow diagrams in system analysis?

Data flow diagrams (DFDs) serve a critical role in system analysis by providing a graphical representation of how data flows within a system. This includes showing the movement of data between processes, data stores, and external entities. By illustrating how data is processed and the relationships between different components of the system, DFDs help analysts and stakeholders understand the data interactions that occur.

DFDs help in identifying inputs and outputs, clarifying how data is handled, and detecting inefficiencies or bottlenecks within the system. They facilitate communication among technical staff and non-technical stakeholders, ensuring that everyone involved can visualize the data flow and comprehend system functions more readily. This is essential for system design, improvement, and documentation.

Other options do not correctly capture the primary purpose of DFDs. Providing a detailed coding language is more aligned with programming and implementation aspects rather than analysis. Evaluating user access levels pertains more to security and access control assessments, which is a different focus. Simulating network performance under load relates to performance testing rather than data flow depiction. Therefore, the choice that accurately reflects the primary function of DFDs is the graphical representation of data movement and storage.