What & Why?
Both the WHAT; the understanding of the objectives of Systems Engineering, and the WHY; the rationale for doing Systems Engineering, are weak in junior teams.
How?
The HOW; the techniques for executing the tasks of Systems Engineering, are also poorly developed within junior teams and require active coaching and mentoring by senior experienced personnel. Note: Age, or years of service, are not equivalent to experience! A better criterion is exposure to full life-cycle successful projects.
Key Systems Engineering Techniques
Systems Analysis; functional partitioning, functional decomposition, functional and architectural allocation.
Specification Generation; how to structure a specification to be internally functionally structured and to operate within an overall specification tree.
Requirements Writing; how to craft an unambiguous, verifiable statement of requirement.