- what drive the need of decommission?
-- budget or operation requirements?

-- instrument exchange requires minimum 5 members.
-- applying queue-mode operations for existing instruments should change the way of observation programming. e.g., assign observing run of an instrument to specific period(s) is possible and it reduces the number of instrument exchanges.

- quantitative measures / matrix is required for decision.

- publication survey: resutls reflect performance of past programs. we need information for future surveys.

- uniqueness of Subaru for Japanese community (not internationally)

- instrument line-up coordination with Keck, Gemini
-- coordination with Keck and Gemini is critically important
-- future of Keck, Gemini cannot be determined by inputs from Subaru community. Risk of losing capability by decommission of instruments for other telescopes.

- HDS
-- transfer to GTC: no discussion since then
-- transfer to Gemini: will lose blue sensitivity
-- also good as back-up instrument
-- HIRES: large mirror aperture

- workload fro commissioning of PFS

- prospective budget in 2020s
-- need to talk with NAOJ HQ

- detailed comparisons with other instruments