Sequence Model Goals

This document contains initial thoughts about changes to the sequence model and the impact they could have on the UI. The ideas are still pretty rough but the hope is that this will provide a starting point for discussing and refining our goals.

• Flatten the entire sequence hierarchy into a single node.

• Combine instrument, obslog, sequence, and at least part of the seqexec UI into a "Sequence" node.

• Allow multiple sequence nodes per observation.

• Internally each sequence becomes a simple list of steps, so there is no need to generate it every time it is needed. The UI will be a challenge.

• And/or logic between sequence eventually? Then not needed between observations?

• Need a way of identifying sequences in order to queue them. What is the impact on the QPT? How is planned time computed? What about observation status if some sequences are complete and others not? Many issues to work out.

• There is benefit to switching to this model even before allowing multiple sequences. In other words, I think the work can be split into major phases starting with a single sequence per observation.

  • Flat sequence model and basic sequence editing.
  • Combine obslog and sequence node.
  • Multiple sequences per observation.
  • And/or logic.
  • Seqexec controls.