Functional Requirements Status and Plans

1. Functional Requirements Status and Plans Christopher Neyman W. M. Keck Observatory Viswa Velur California Institute of Technology Keck NGAO Team Meeting #10 September 17, 2007 012 Robison Laboratory

2. Outline • How to find the FRD drafts and other materials • Status of AO and laser FRD draft 0.2 • Thoughts on long term requirements management • Discussion

3. FRD: How to get there (Twiki) Use this Link

4. FRD: one stop “shopping” (Twiki) Links to current supporting documents http://www.oir.caltech.edu/twiki_oir/bin/view.cgi/Keck/NGAO/FunctionalRequirements

5. FRD: AO and laser drafts v0.2 (Twiki) closer to v0.2 closer to v0.2 http://www.oir.caltech.edu/twiki_oir/bin/view.cgi/Keck/NGAO/FunctionalRequirements

6. FRD: AO section status v0.2 • Required functionality well documented • Specification need work, values are still TBD • Traceability needed • Who was the source of the requirement? • Revision history • Approval status (draft, final, approved, pending, dropped) • Science → system → function, • Numbering scheme: not consistent between documents (ScRD,SRD,FRD) • Rational needed • Why this requirement is needed • What reference material supports it

7. FRD: Laser Guide Star Facility section status v0.2 • Laser status • 27 pages of requirements • Tried to cover the bits that make NGAO system different from K1/ K2 LGS. • Have received some inputs on the draft. Need more at this point. • Required functionality well documented • Specification need work, still some TBDs • Needs some work in integrating and cross referencing tables wrt the main FRD. • Other specific requirements that spring up during this phase will need to be added. • Traceability • Rational needed • The need/source of most requirements is indicated in brackets with italicized text.

8. Total NGAO requirements will be large • Still have FRD sections for instruments and science operations tools • Preliminary design and detailed design • Draft subcontracts from main NGAO requirements • Other systems that are smaller in scope • MOSFIRE: ~700 requirements • NGWFC: 342 requirements • MAGIQ: ~300 requirements • NGAO detailed requirements estimate AO = 8*NGWFC ~ 2700 LASER= 4*NGWFC ~ 1370 Ops. tools=4*NGWFC= ~1370 Instruments = 3*MOSFIRE ~ 2100 TOTAL ~ 7500 requirements

9. Will we ever need to know the following? • The origin of a requirement (backwards trace) • Affects of a requirements change, such as the impact on a design, interfaces, and/or subsystems (forward trace) • The most important requirements, especially if resources limited • The highest risk requirements • How a requirement will be tested (inspection, analysis, demonstration, test) (compliance matrix) • A requirement has been satisfied (compliance matrix) • Requirements that are unaddressed or unassigned

10. Requirements need supporting information • The source of the requirement (who nominated it) • A unique identifying number for it • The rationale for the requirement (why is the requirement needed?) • Change history (how has the statement of the requirement changed over the system life?) • Traceability (of each requirement to its source) • Status (draft, final, approved, pending approval, disapproved) • Assigned to (which subsystem or component of the system)

11. Requirements need supporting information • Also useful to capture the following: • Its priority (on a scale of one to three) • Its relative cost to implement (low, medium, high) • Its relative difficulty to implement (low, medium, high)

12. Thoughts on requirements management

14. To automate or not to automate • Group could consider automated tools • Software industry • Database used at Keck NGWFC and MAGIQ • LLNL, JPL, TMT (What do they use?) • Better suited to bigger project • Choice of process or knowledgeable scientist, engineer • Resources limited Thanks for listening: discussion or questions?