For example, if lack of resource commitment is identified as an issue, then what would the contingency plan look like? does it have a specific structure? what key factors must I consider when implementing a contingency plan?
A contingency plan is a set of actions you would deploy when certain predefined variables have been met. Prior to those variables coming true, the plan sits on the shelf.
The specific structure of your contingency plan, or any plan, should be defined by you or your organization. It is great to reuse someone else's work but you need to hold the authority to modify it so that it works for you and your project. At the most simplest core, your plan needs to answer who, what, where, when, why, and how. If you answer those all of those questions and write it to the detail where anyone in your profession can pick it up and go, it is a good plan.
Regarding resource commitment, a contingency plan might look like the acquisition of resources from another source if that were possible. If human, you might source out a vendor to supply talent or even hire directly off the street. Your contingency plan would have reserves in order to fund those activities. If materiel or tools, have vendor B or vendor C ready to go if vendor A does not produce.
In the plan, I would identify the variables that have to be present before I deploy. For example, if human, I might use a schedule/finish variance that exceeds so many dollars or days that would trigger my contingency plan.
Hope this helps.