Fireworks, flashing LEDs, klaxons, sirens, something to let the player know that "There's a problem over here NOW!" Just posting a note under the Miscellaneous Quests tab and figuring the player will know to look there in a timely fashion is overly optimistic.

There is already a NPC giving you a flare gun to call for reinforcement, I would love for the settlements to use it when they need help. Semi-regional alarm.

You can build a bell, it could also be used as an alarm. It's more of a local alarm really but useful if you are inside crafting peacefully.

Radio tower built in a settlement? Why not allow the settlements to diffuse a S.O.S ? "Sanctuary Emergency Signal Radio is emitting". Global (or very big range) alarm.

There is so much that could be done with what is already in the game

This is a VERY pertinent point. ALL of the settlements require a Recruiting Broadcast Tower to be effective. Obviously, the arriving settlers listen to their radios. Having them calling on the radio should be as intrusive as a cell phone ringing in a movie theater: annoying enough it grabs everyone's attention.

You can install a siren cant you? I also get a message on the top left (I think its left or its right) saying a settlement is under attack. it flashes a few times.

Is the siren functional? Is it activated when the settlements is attacked? I was attacked recently with all of these things built and nothing was used to signal an attack.. hmm

You do have the siren connected to a generator right?

Yup, I'm pretty sure I have it all correctly set. I use a lot of these things (I love building my own village) so I know how it works... hmm I'll test it more later tonight and re-wire it. Maybe it broke when I moved it (after linking it, happened to me earlier with a radio tower), even though I now always re-wire after I move something.

Anyway, if you tell me sirens DO work when there's an attack, I guess that is the something CaptainPunch was looking for. I'm still pretty fond of the radio+flare idea though

So you never get that message on your screen saying there is an attack? It usually pops up twice when there is an attack if you are off in the world.

I had a settlement attacked and never saw the message. Of course, I was going through a main quest critical story dungeon at the time. I finished and got a message about failing to help the settlement. It's annoying to feel like I had no notice, just because I missed a tiny pop-up in the upper left corner of the screen during an hour of exciting story and gameplay.

Yes I get the messages in the top left corner, what we are talking about here is more "immersive" (yah it's overused, sorry!) way to make us know there is an attack. A message in the top-left is easy to miss, a radio signal or big fireworks (flare gun) is harder to miss and way more in-character than a popup.

the entire settlement section of the game. be it assigning settlers, tracking said settlers/provisioners, alerts for attacks or crafting in general.

needs work in terms of functionality and the user interface itself.

I thought it was obvious that the siren was an alert for the settlement in which the siren is placed. If I'm in Sanctuary and there's trouble in Tenpines, the siren really isn't doing anything to notify me about that trouble.

The notes that pop up are short-lived and get lost in the umpty-umpt other messages that appear there. If it's trouble, I don't want an, "Oh, by the way...." I want a "NOW HEAR THIS!"

I seriously doubt anything will be done with the settlement part of the game, unless modders do it. Some have said building walls is pointless mobs just spawn right inside the settlement.