What does the integration process help establish?

The integration process is crucial in systems engineering as it focuses on combining different components and subsystems into a cohesive whole, ensuring that they work together effectively. By establishing system internal interfaces, the integration process allows for seamless communication and functionality between various parts of the system. This is essential in ensuring that subsystems do not operate in isolation but rather cooperate to achieve the overall system objectives.

Effective integration also involves verifying that the interactions among components align with the design specifications and system requirements. While the other options relate to important aspects of systems engineering, such as defining design specifications or ensuring maintenance capabilities, they do not specifically highlight the role of the integration process in managing and clarifying how subsystems interface and interact internally. Thus, focusing on system internal interfaces is central to the integration process, making it critical for the successful development and deployment of complex systems.