Here is my list:
scarce critical skills
competitive talent markets and buy, build, JV innovative approaches
Talent mobility opportunities and barriers
Emerging critical skills
Projected retirements
Disengaged talent segments eroding pipeline

Terry - I fully appreciate your question. I am also aware that to fully engage with you is way beyond the capacity if this type of exchange - my brief offering is that to handle such situations today requires an holistic perspective and the ability to select methods and practices that create the life conditions for human thrival. My brief response I hope explains why this type of exchange is lacking the ability to embrace this root cause thinking and leads to nothing more than a haphazard exchange iof models tools and self seeking biases. I hope what I have written helps you in a manner that matches the spirit of my intent. With gratitude. Christopher

Terry. As others have said this is a big topic so hard to cover fully here. However, from your notes, you say you have started from your current hierarchy, and I'd say that's the weakness of the current plan. I don't know how far out you are trying to look, but even 3-5 years out in most organisations these days you can't assume the structure will stay the same. So I'd say you need some initial scenario planning for the business, ideally with some strategy people involved, to look at 3 or 4 different scenarios for how the business might need to adapt and evolve. That will then stress test your workforce plan, because you will have made assumptions that don't necessarily hold true.

My other piece of advice is to get as wide a range of people as possible to look at the plan and challenge your assumptions. The future is inherently uncertain, and no single perspective will cover everything, so the more views you have the more chance you have of the plan being robust.