1. Name the system scope and boundaries.

Track changes to this initial context diagram with the in/out list.
• In/Out List
2. Brainstorm and list the primary actors.

Find every human and non-human primary actor, over the life of the system.
• Actor Profile Table
3. Brainstorm and exhaustively list user goals for the system.

The initial Actor-Goal List is now available.
• Actor-Goal List
4. Capture the outermost summary use cases to see who really cares.

Check for an outermost use case for each primary actor.
• Design Scope Diagram
• Use Case List
5. Reconsider and revise the summary use cases. Add, subtract, or merge goals.
   Double-check for time-based triggers and other events at the system boundary
6. Select one use case to expand.
   Consider writing a narrative to learn the material.
7. Capture stakeholders and interests, preconditions, and guarantees.
   The system will ensure the preconditions and guarantee the interests.
8. Write the main success scenario (MSS).
   Use 3 to 9 steps to meet all interests and guarantees.
9. Brainstorm and exhaustively list the extension conditions.
   Include all that the system can detect and must handle.
10. Write the extension-handling steps.
    Each will end back in the MSS, at a separate success exit, or in failure.
11. Extract complex flows to sub use cases; merge trivial sub use cases.
    Extracting a sub use case is easy, but it adds cost to the project.
12. Readjust the set: add, subtract, merge, as needed.
    Check for readability, completeness, and meeting stakeholders' interests.

analyze data: derive scientific results from reduced data

configure: setting up some subset of the telescope by a "telescope expert" taking into account distortion, desired frequency, FFT vs. autocorrelation,  LO, precision, etc. that are specific to the GBT to get the system to produce the correct "product."

operational: able to be used but not necessarily configured for use.

preview image: results of an automated data reduction performed by the data reduction pipeline.

reduce data: take out instrument specific effects, collate FITS files across devices and scans

select: deciding on the correct telescope setups for the targeted observing by an astronomer based to the desired science.

SuD: (System under Design) NRAO provided GBT observing system

• How much can the configurer do for observing?