Lifecycle Computer

There's an option in the asset under the Lifecycle tab for "Maintenance" where you can select a Maintenance Contract or Create a New one. You can also access this through "Contracts" in the Procurement menu. When you open a new contract, you can enter all of those details there, including "Start Date" and "End Date". The End Date will be particularly important for what you are wanting because on the right, there is a "Renewal Reminder". This allows for an automatic reminder to be sent to whomever you choose from your technicians (for example: All Admins). Once you have completed your New Contract, you can go back to "Assets" and assign it to the computers that fall under that date range by going to the asset, clicking "Lifecycle" and then going to the "Maintenance" section and adding the contract. I'm sure there is another option, but this honestly seems the best option to me based on what you are requesting. 

This will also help when you go to edit a "View", as you wanted, to see all computers older than 3 years. You can click the blue "Edit View" in the Computer Assets page. Then for your "Attribute" select "Maintenance Contract" and select the particular Maintenance Contract you want to view (i.e. the ones that are older than 3 years). You may want to name your Contracts with the year so you can easily select the proper view.

Thanks you for your fast and clear explanation, actually it's quite similar as the "Lease Contract".

Do you know if that could be automated each time a computer join SW ?

You're welcome! I am looking for ways to automate it still. I'm not necessarily seeing anything so far but I will keep looking. Also, forgot to change the above picture to a Maintenance contract (it says software license). I saw you can add the Asset as an item on the contract as well if the asset is already on SWSD. I will let you know if I figure out any automations with this though. It seems like it should be possible but if not, would be a great feature request.

I might have found an easier way that includes automations and fits your needs. When you add your computers, does it include the warranty status?

I might have figured out a different route that allows automation.

First, you would create custom Field. I just did a mock one called "Contract Group".

Then, you would create a custom form on "Contracts" and have the login to show the "Contract Group" when it is Maintenance.

Then you would also add that field to show on the "Computers" custom form (no logic with that one).

Then you would create a Dynamic Form Rule That is set to show the field with the scope "Contracts". Once you create that contract, you would choose the contract group name. This is essential as it sets everything in the automations into motion.

Next, you would create automation rules. The first would be triggered by "Object Created" in the "Asset" Scope. Then, your condition would be the category of the asset or it could be department, site, whatever works specifically for your company. Since this is triggered once the object is created, you could then set the action to "Update Record" and the Field to your custom field "Contract Group" and the value to whatever values you entered there. You would set other automation rules to trigger on different categories (or whatever field works) adding them to the proper contract group once the asset is added to Service Desk.

Finally, you would create your contract (and you can copy the contract and just label each contract with the appropriate contract group from the drop down menu) and you could do what I posted before with the Renewal Reminder notification on the contract.

Obviously, this is a lot of steps. And maybe there is another way to do this with Automation rules. You may even be able to send the notification through Automation rules. But once you have it set up, it will automate just about everything and make the process more to what you were asking for.