Bored.. you seem to be doing a good job a due diligence for your building. I however believe strongly that you should employ the services of a consultant for your project. They will pay for themselves before the project even begins. You will never be in a better situation than to have a major company (Otis TKE Kone Schindler) install and maintain their own equipment. You will benefit in the latest technology and worldwide experience You will benefit from tech bulletins, recalls, software upgrades, trained personnel, expedited processes, process improvement and hopefully can prolong obsolescence. as long as you maintain that full service contract and good relationship for the life of your equipment.
Despite what all the majors say..their equipment is proprietary. MOst every Otis mechanic can, diagnose, repair, test, adjust an Otis controller. They have the tools, manuals and contacts. Very few non-Otis mechs can even perform the few tests required annually on anOtis controller without the proper service tool. It is no different when an Otis guy works on a Kone or TKE controller. As long as you maintain the relationships..All is good.
But relationships are tough these days.It is hard to not feel like you are being taken advantage of your maintenance provider when they charge you $500.00 an hour to restart an elevator after a power outage. Or to replace a door that was knocked off track by a mover. How about $20K for a bucket of water spilled down the hoistway (shaft).
You should reward Otis for 28 years of great service by allowing them to bid on your work and give them any preference they deserve. But your consultant will write a specification and more importantly a new maintenance agreement that serve you well for many years.A large modernization project gives you power to negotiate. Take advantage.