I was just wondering if there was a single word to represent the phrase "something that is available/accessible all the time". The context for this is a company that provides services related to information technology.
There is ever-ready.
Permanently accessible, available, or prepared: 'Roxie’s ever-ready smile'
There is handy also which is more common.
Readily accessible: found a handy spot for the hammer.
Note: I gave my answers based on the exact definition only. There are different words and phrases that can be used based on the context. If it is related to information technology services, using "available 24/7" would be better.
at hand means ready for use. (dictionary.com - 43c)
We keep a supply of canned goods at hand.
It depends a lot on what you are talking about and in which register.
In a formal context I'd try to use ubiquitous. It doesn't imply constant availability but constant presence though, and refers more to "everywhere" or "in every situation" than to time itself:
The internet is almost ubiquitous thanks to smartphones.
In other contexts, available 24/7 (as Spehro suggested) emphasizes time.
— on standby
: ready or available for immediate action or use
It is a constant: always there, no matter what.
Pierceall in OrangeCounty Register, Feb. 24, 2014:
And as ideas for the park have come and gone, political administrations have changed and a recession had slowed the pace, Croucher is a constant at events and city meetings, gently reminding officials that he's still there and still wants to build a museum.
Leaderhouse in Prince Albert Daily Herald, March 03, 2014:
Everywhere you go (Bob) Marley’s photo is seen and his music is a constant at almost every turn.
Tascon in Vero Beach Newsweekly, March 12, 2014:
Davis is a constant at many functions with his knack for getting guests to reach into their wallets and purses to help a good cause. He uses serious fundraising techniques and humorous jibes to encourage higher bids.
This term gets used to describe things like internet connections that are always present without a dial-up, handshake, or log-in process.
The implication is that when you open your browser the internet is there.
So, it definitely describes the IT sense that you mentioned in comments.
An always-on connection.
An always-on resource.
In the tech world, the phrase is usually high availability. In adjective form, it would be highly available, as in
The cloud computing salesman quoted me $300 per month for a cluster of highly available database machines with 1 TB storage.
This has become (or perhaps always was) more of a marketing term than a technical term. But High Availability is usually backed by a contract, typically called a Service Level Agreement (SLA), which contains the exact definition of availability. Without a contract, high availability is just a buzzword (like "Organic!" or "state of the art"). The wikipedia page has further details on these concepts.
To summarise the information I've gleaned from the question and subsequent comments:
- You want to describe something that is always available.
- It is referring to something IT related.
I'm not sure if it's right for you because we have very little information, but here are some suggestions specific to IT.
- Mission Critical component.
"Component Z is mission critical, and as such is always online."
- Permanently online/available.
"The ISP is able to offer a permanent internet connection."
- Uninterruptible connection (taken from UPS).
"Available 24/7, the service is uninterruptible all year round."
Referring specifically to services in which a person is required could be done with:
- On Call
"Our technicians are on call 24/7."
I realise none of these cater perfectly to the OP's requirements but sometimes the OP doesn't know exactly what they want until they're presented with an option they never explicitly asked for.