Checklists

[Airliner]

How important is it that each specific step in a checklist be performed exactly as written? I raise the question because, it diving into
PMDG's 737-700, I have found multiple checklist flows and each one is different! Now, I understand that basics must be followed, like
checking the parking brake before starting the engines; programming the FMC before takeoff, etc. But, there's a bunch of items that
seem to pop up in different places, such as Yaw Damper. One checklist has it at the beginning, shortly after bringing the ground power
online. Another holds off until you are ready to taxi. Is there a place to find official checklist flows for this aircraft (real world) or is it fine to
tailor them to each operator, within basic guidelines?

(In fact, the procedures in the PMDG docs conflict with a tutorial done by a real pilot, who doesn't fly the big iron but has spent time in UA's
simulators.)

[CowlFlapsOpen]

Some items have flexibility, but in general there are reasons for why something appears when it does. it is best to understand what the items does or
what systems and settings conditions it requires. The yaw damper cannot be on during take off, for example, so there is usually a checklist item
verifying when it is off and when it is on. On the other hand, you can set your nav radios before leaving the gate or during taxi in some aircraft. A
checklist is there to avoid doing something or failing to do something. If it is on the checklist it is generally not optional.