End Of Life EOL

Hey Craig,

for macOS, Apple usually supports the last two Versions of OS, so current is SIERRA (10.12.x) - therefore ElCapitan (10.11.x) & Yosemite (10.10.x) are receiving Security Updates.

I have 2007 iMacs in our Staff Canteen, that are fast enough with a small SSD Drive, running El Capitan just fine.

And I have 2009 & 2011 MacMini in some Conference Rooms as Residential Computer with a Webcam for Web Conferencing, etc.
so if you care for your Equipment - it can last a long time. But also newer 2015 MacBookPros & newer Equipment...

In regards to iOS, as long as you don't do Security relevant Stuff, like Online Banking / Online Stores / Credit Card Transactions - you can use even older Devices - I still have iPad2 on 9.3.5 - as Picture Frames or simple Remotes -

otherwise I have about ~70x 5th +6th Gen. iPod touch in use on iOS 10.3
and we replaced iPhone 5s for iPhone7 at the beginning of this year (2017).

We also have some Apple TVs & I am replacing the few 3rd Gen with 4th Gen Units...

And I hope that Apple updates the MacMini soon (!), they are on my Wishlist on top at present...

Anything that touches our Corporate Network - I go for Devices with the latest macOS / iOS Versions - anything that sits on our Guest WIFI Network can be more mature...

Corporate Network connected Equipment is replaced every 5 years, before it reaches Vintage Status.

So I would suggest:

2015 MacBook + Mid 2012 MacBookPros, simply in order to use all the Features of mac OS SIERRA
Along with Late 2012 Mac Minis & iMacs AND Late 2013 MacPro Apple Requirements for macOS Sierra

iPad 4th Gen should be your oldest iPad Version!
iPhone 5s should be your oldest iPhone
iPod touch 6th Gen be your minimum, same goes for AppleTV (4th Gen.)

We stop deploying/supporting the OS when Apple appear to stop releasing security updates for it (usually when they release a new one and this version becomes current-3). We offer in-place upgrade to the current macOS via Self Service for staff, but will force the in-place upgrade of of it for machines running an OS older than the last 2 versions.

Previously, when 10.9 stopped getting updates, we sent out lots and lots of comms to colleagues still running it, asking them to arrange a re-image (the 10.9 build was full of cruft and we didn't want to do in-place upgrades to it). We set a deadline which was a few months after 10.12 was released, then MDM locked anything still on 10.9. Security was enough of a reason to do it. Three months later, we still have 7 Macs sitting on a lock screen somewhere with nobody coming forward to get them upgraded...

For security reasons, important to stay current on iOS. For macOS, current plus the two previous versions (that Apple provides patches for).

Presumably 10.13 will drop this fall, and that will mean 10.10 scrolls off the "supported" list. We've already been notifying the responsible parties for the handful of 10.10 servers we still have in our environment (no end-user facing machines, they're all being transitioned from El Cap to Sierra over the next couple of months).

Also, hardware that exceeds 5 years since purchase date is surplused (US .gov).

--Robert

thank you everyone I am in the process of building a EOL protocol for our college and appreciate all the input

We only support the current and last two OS versions (due to Apple's security update policy which is the same). As for hardware, we recommend replacing the machines when their extended warranty runs out. Not for a specific reason regarding the warranty, but 3 years is the typical depreciation on hardware. Our accountants want us to keep desktops for longer though, so about 5 years for those. Our laptops are generally pretty heavily used so 3 years is a pretty good call. Sometimes an older machine that's still in good condition will get handed down and the prior owner gets a new machine, but it's not often.

Depends on how your hardware is used. And what it's for. If you're doing high-end video editing then you'll want to replace it more often. If it's web browsing and office work, then you can keep it in production longer.