Military staff work is not glamorous, but it is how a good Commander builds effective, robust, and executable plans and operations. Planning is the first step towards success.
"How do you eat an elephant?" is an old question, and the old answer is "One bite at a time." The parable is that you can conquer the seemingly unconquerable by taking a systematic approach to break it down. One of the ways we do this is "targeting" our efforts to where they will be most effective. If you only had a single bullet, where would you most effectively use it? If you only had one operational cell? If you only had one platoon? These are the questions that get asked to determine priority, and a lot of thought and arguing goes into determining where something falls in priority.
The term "HVT" for "High Value Target" and the spin off term "HVI" for "individual" describes assets that an opposing organization needs to accomplish their mission. This can be organic command and control channels, logistic supply chains, propaganda cells, or whatever else that the organization truly needs to accomplish their mission.
The "High Payoff Target" or "HPT" is something that we can gain a marked advantage over the opponent from killing/destroying/isolating/neutralizing that asset. Once that HPT is gone, is isn't readily replaced.
You would think that HVT and HPT lists would be the same. The reason they are not always the same is that we like to break down missions by phases or geography.
The difference is largely academic to the ground pounder, who is mostly given a "priorities of engagement" list (radios, crew served weapons, etc). The difference comes up in the planning cycle as to how to prosecute war and engage the enemy. So the higher up the food chain you get the more important HVT and HPT lists become.
One of Saddam Hussein's known objectives was to protect Iraq. He chose to do this with an Integrated Air Defense network of Surface to Air Missiles, Command and Control nodes, all meshed together over a communications network. So his "HVT" could be classified as "IADS" assets. When we smashed through that IADS asset (twice in my lifetime, once in my career) we targeted portions of the system with different tactics and munitions in order to gain Air Supremacy. Our "High Payoff Targets" weren't the SA missiles themselves, but the backbone that would make those missiles effective. A million missiles does you no good if you don't know when and where to use them. Knocking out radars and C2 nodes was more effective than targeting the missiles. Iraqi HVT was the IADS, our HPT was C2 nodes and radar sites. Sorry for the rather simple explanation.
In a conventional war we usually have a systems centric HPT list as we have a pretty good understanding of how the enemy conducts business, how assets are used by doctrine, and how effective/trained/disciplined the opposing force is. In an unconventional war we have very little of that going into the conflict unless someone has been paying attention. When we went into Vietnam there was already over a decade of history on the VC that we could have used, but we didn't. However I have seen enough to know that we won't make that mistake again.
The takeaway point here is that effective forces minimize "single points of failure" in their organization. If every one in your organization can shoot effectively out to the maximum effective range of their rifle, does it really do your enemy any good to mount an "anti-sniper" campaign to take out your best shot? If every one in your organization can effectively make improvised munitions and conduct demolition operations does it do your enemy any good to try to target your "Sappers"? Single points of failure can find themselves on the HPT list very quickly. How many times have we seen "financier" on the target worksheet because he is the only source of revenue for an insurgent?
This is one of the reasons that American forces have done better in Afghanistan than Soviet forces did. There are much fewer single points of failure up and down the chain of command with the American model. The average "grunt on the ground" between the two forces was largely interchangeable (sorry Americans, I know you are better educated with better toys but in reality your Soviet conscript was just as effective). But now taking out a vehicle doesn't stop the unit from communicating, the American Infantry Platoon can continue to fight even after losing a PL or Squad Leader because they train junior leaders to step up.
If you find your organization relying on one asset, you need to stop doing that. Build redundancy, or get eaten up one bite at a time.