The Lear 60 and the Challenger 605 should go away. What a waste of money to Proline 21 those things while the Global has the oldest avionics of the whole lineup. The 60 can be replaced by taking the Challenger 300, calling it the 250, and taking some gas out of it. Maybe shorten it up and make it seat seven instead of nine. The 605 can be replaced by taking the 300, upping the thrust some and adding the amount of gas it should of had so it has 4000nm range. Want a bigger cabin? The extend the Global range so you have a 4000 model that also has 4000nm range but with the big cabin.
Two less airplanes to support and maybe Bombardier can stock parts and beat someone other the Saberliner in the satisfaction survey.
The 605 and 60 are money makers because the tooling was paid off long ago, but they are no longer competitive. The 60XR is a total hack job. APU is still fussy, it's the same wing, and even the Proline 21 is only half installed. The ICAS didn't make it, so you still have annunciators.
How can you say the 605 is no longer competitive. It offers a legit internatioal aircraft at 9-10 mil less than the global 5000. If you start moding the 300, you increase your manufacturing expenses for no reason. You already are making planes to fit that market.
I don't know anything about the 60, but the 605(604) offers a great size cabin and good range. Dispatch reliability is incredible and it is a good solid airplane to fly.