Which of the following is NOT a primary task during the integration and testing phase?

During the integration and testing phase, the main focus is on ensuring that all components of the system work together as intended. This involves checking for bugs to identify any issues in functionality, verifying interoperability to ensure that different system modules or external systems can communicate and function together smoothly, and creating process diagrams, which are often used to visualize workflows and ensure that all parts of the system are properly integrated.

Writing the actual code is a task that typically occurs in the earlier phases of software development, specifically during the coding phase. At this point in the process, the emphasis has shifted to testing the system that has already been built rather than creating new code. Therefore, this choice stands out as not being a primary task during the integration and testing phase.