A systems engineer works on complex systems from the start to finish of a systems life. Systems engineers will begin the process by translating a loose set of requirements into a formal requirements document. These requirements will be carefully analyzed to determine what technologies will be used to satisfy the requirements. All requirements might not be able to be satisfied, so it is important to understand which are the most important (must haves) and which are less important (nice-to-haves). This interpretation leads to a conceptual design that can be analyzed and refined during the design process. Each modification to the design has to be analyzed for the effects on the interdependent pieces of equipment and against the requirements - this process can take a long time, but the work done here is much easier and cost effective than trying to diagnose issues with a system once it is deployed.
Systems engineers also work in the implementation of the system with the end customer (the customer was the input for the requirements). The implementation process involves developing a comprehensive test plan, configuring various sub-systems to work specifically as the customer intended and eventually getting agreement from the customer that all the agreed-upon requirements are met satisfactorily.
The final areas where systems engineers will work is to develop maintenance plan and a decommissioning strategy. These activities actually begin their development during the design process, but a system engineer generally manages these activities to account for changes in subsystems and unforeseen changes in technology obsolescence.
The day-to-day activities for a systems engineer are varied - some days are spent interfacing with customers in a design review, others may be spent in the lab modeling system behavior, while others are spent troubleshooting complex systems to find the source of an issue. There is no set day for most systems engineers and that is a something that those who choose this career field enjoy.
Lance recommends the following next steps:
Congratulations on wanting to explore a very interesting area! I am presenting two sites that will tell you specifically about Systems Engineering and about Engineering in general
Send thank you notes to those who help you. Please keep me posted. I would like to follow your progress. Enjoy your journey!!