The resilience of business operations heavily relies on the underlying IT infrastructure and the applications it supports. Not all applications are created equal; their importance varies based on their role and impact on business continuity. This concept has given rise to the classification system known as “availability tiers.” These tiers help organisations prioritise their resources and manage risks effectively by aligning the criticality of applications with the appropriate level of support and infrastructure resilience. Today, we will explore the different availability tiers, from mission-critical applications that require 24/7 uptime to less critical systems where temporary downtime has minimal business impact. This discussion will provide insights into how businesses can optimise their IT investments and enhance operational reliability according to the specific needs of each application tier.
Today, we are going to talk about availability tiers. And the reason for that is that your applications aren’t born equal. Some applications are really important, and without them, your business might not function at all. Others have to work at some point, but it’s not the end of the world if they don’t. It’s really useful to go through your applications and to grade them in which availability tier they’re in, so that you can make sure that the infrastructure they sit on and the way it can fail over is suitable for your business. Typically, application tiers might range from tier zero to tier three. Tier zero being mission critical. They’re going to be available probably 24/7. Without them, you’re out of business. A lot of people are impacted, and that’s really expensive. Examples of this in the past that we’ve worked on might be banking payments. If you can’t send the payment, then people are really impacted, and that’s very bad. Regulatory fines are a complete mess. So, banking payment systems have to be tier zero, mission critical. High impact, tier one. That is where your major pain is. Customers might be unhappy, and it’s going to cost you, but you might not be out of business.
This might be problems with your click-and-collect service on your website. People might still be able to go into your store, but they might not be able to order their shopping right now. They might be able to come back in an hour. It’s not the end of the world, but it is really impacting your business. So much pain. That’s going to cost you money. You just don’t… Not quite everything, but it’s going to cost you some money, and you really want to avoid that. But then other things might be medium impact. That might be when it’s highly inconvenient. There may be a workaround. It might cost you some money. There may be some impact. But it’s not the end of the world. An example of that might be in-store self-scan systems might not be working. Now, that’s annoying, but you can still go to the checkout. It’s not the end of the world, but you don’t want it to happen because it does annoy people. And then similarly, you’ve got low-impact things. That’s when either a few people are affected, or it’s not time-critical; the impact is minimal.
That might be when I get my sales report for the day. If that doesn’t come today, it’s annoying, it doesn’t really make that big a deal. So, given the fact that you’ve got this spectrum of available sustainability, typically, what you need to do is you need to look at the cost to run versus the cost of the impact because the more that you do to make things available all the time for them to fail over or be highly available, it costs money, and it costs time to do that. So you have to make sure that the systems you’re investing in are the ones that are really worth it. And the other thing is that for most people, you can’t solve everything, particularly you can’t solve everything at the same time. So this gives you a bit of a roadmap as to where you need to prioritize. If things are in the wrong bucket, you need to action them. But what’s your priority? The priority is making sure that your tier zero is up to scratch, and then you can work out from there making sure that everything works as well as it needs to.
So that’s a quick look at availability tiers, why they’re important, and then what we can do after that is talk about some of the solutions you might implement for each of these tiers.