Service level agreements (SLAs) and marketing material that emphasises extremely high 'five nines' availability – 99.999% of uptime – can sometimes have the opposite effect.

In fact, almost always-on availability can nudge operators away from taking systems or infrastructure down for maintenance, according to Simon Brady, EMEA services channel business development head at Vertiv.

"Everyone talks about 'five nines'; 99.999% availability," Brady says. "Ask any data centre when was the last time they had a three-minute failure; a one-second failure equals a whole day. ‘Five nines’ is a misnomer, a marketing gimmick."

Always-on data centres are unrealistic

The impetus on data centre five-nines might have inadvertently contributed to the data centre cooling issues reported during 2022's July heatwave, when outdoor temperatures peaked at 40.3ºC in Coningsby, Lincs. Rather than carving out downtime necessary to upgrade equipment or maintain systems to cope with extreme temperatures, operators paid the price much later down the line when cooling systems failed.

While hot weather can correlate with failures, well-looked-after equipment doesn’t typically falter. Instead of demanding constant uptime, stated metrics and service levels should focus more on those aspects: contingency plans in the case of failure, resilience strategies, or redundancies built in at the software level, for example. he says.

Some data centres, meanwhile, otherwise typically operate beyond their SLAs and contracts, putting their own organisation at risk – legally if not technically. The promise of 99.999% availability, therefore, could be deemphasised in some cases, Brady suggests.

"No matter what you buy, whether it's a Bugatti Veyron or a Ford Focus, if it can break, it will break at some point," he says. "So you have to plan for that."

Sascha Giese, head geek at SolarWinds, agrees that 99.999% uptime often falls "somewhere between a marketing statement and a tick-box exercise for business requirements", with organisations sometimes seeing 'five nines' as standard even if they don't need it.

"'Five nines’ allows just over five minutes of downtime in a year. Even if nothing happens, that's not easy to achieve, as OS and security updates will take longer than that. This means data needs to be moved around between redundant systems," Giese points out.

Smaller or regional companies might be "perfectly fine" with two nines, considering that maintenance windows can be scheduled outside business hours. Yet "we live in a world where humans have lost their patience". Either way, "unexpected details" should be avoided in the fine print, he cautions.

When disaster strikes, ‘five nines’ mean nothing

Giese agrees more tolerance for some downtime can be needed, suggesting that a staging site with "proper messaging" could be prepared, "ready for the inevitable" disruption, which is bound to happen at some point. Other than that, customers should perhaps simply be more prepared to pay higher prices if they want that high availability.

Neil Clark, director of cloud services at provider QuoStar, notes that typically the need for downtime should be – and is – outlined in the fine print. The onus is at least partly on customers, who need to make sure they know exactly what they're being sold in the first instance.

"Downtime from a maintenance perspective shouldn't ever be included in your 'five nines'," Clark says. "If they can't have an application that ever goes down, even for maintenance, you then build the solution right for that application. But, from our perspective, we're going to have maintenance, our platform will have maintenance, the provider will have maintenance."

That might suggest providers could make the service levels and maintenance requirements clearer to customers, perhaps by explaining it in the main body of an agreement, rather than in the fine print – and emphasise the importance of engaging with all the terms and conditions.

"Obviously, honesty is the best policy," says Clark. "And looked at another way, 'five nines' means absolutely nothing if there is a natural disaster – like a flood. I mean, how much diesel have you got to run your data centre if something like that happens?"

Reforming the ‘five nines’ mindset

Nick Archer, senior consultant at datacentre authority Uptime Institute says 'five nines' can still be useful as a metric, partly depending on whether customers are working with collocation or cloud, and what services are being hosted or supported.

He warns that if critical business functions are in a third-party facility or the cloud, five minutes of downtime may not even be considered enough anymore. If purchasing a single supply to a rack, however, with single corded devices, it's probably "the best you're going to get".

If there's "a concurrently maintainable or fault-tolerant infrastructure", downtime can, of course, happen for maintenance.

"I think 'five nines' remains a useful metric but it is probably a little bit outdated," Archer says. "And Sod's Law states that that five minutes [downtime] is going to be happening in whatever is critical to your business, whether that be key trading hours or key business hours in the middle of a key application."

Customers aren't necessarily realistic when estimating their own tolerance levels. If you were to ask different stakeholders within an organisation, they'll all have different views. Providers should ensure stakeholders agree and understand in the first instance the potential impacts of downtime, then work on reducing risk, says Archer.

What's key is understanding the importance of the application or the service that's been supported that's going to be placed elsewhere, related to the tolerance of the organisation for potential risks, outages or downtime at particular times, he says.

There are numerous reasons why an organisation might want or need to change IT service provider, but once the decision to move has been made, it’s down to tech teams to make the magic happen. Except it’s not magic – it’s hard work. It takes time and careful planning, and there are many potential pitfalls along the way, but having a strong tech team will ensure a smooth transition.

Plan to review, review to plan

Switching to a new IT services provider starts well before the switch itself is made. It’s important to build regular reviews into IT services provision, and key that any contracts can accommodate those review periods; it’s not helpful to be locked into a long contract with a provider when you know you could be getting a better deal elsewhere.

Kenji Matthews, IT manager at architectural practice Stephen George + Partners took the firm through a transition to a new IT provider and tells IT Pro: “We build in review periods in our contract, on a three-year basis. We fix the price and agree on the service level, and it is at the end of that three-year period that we look into whether the IT provider has delivered on the set agreements.”

Ash Patel, IT director at private equity firm ECI Partners uses a tighter time-frame. He says the company works really closely with its provider, explaining: “We truly work together to build a strategic roadmap on a short and long term basis, which is revisited every few months to make sure we’re on track.”

Patel offers some advice about contracts too, telling IT Pro: “Before signing any new agreement, businesses should make sure that the exit strategy and associated costs have been outlined to avoid unforeseen spending.”

Get buy-in from the top, and plan, plan, plan

When it’s time to change, it’s time to plan and support is needed from across the business. Patel tells IT Pro that a number of board level roles are crucial, saying: “The CEO and CTO/CIO/IT Director will play a pivotal role in ensuring that the business is bought into the changes, but also that it’s equipped for them.”

While board level buy-in is crucial, and the board is ultimately where the decisions will be taken, the role of IT managers and the whole tech team is no less important. Indeed both the board and tech team are vital for ensuring wider support across a firm, and that can’t be given enough importance. Matthews tells IT Pro: “Making sure employees and users feel included in the process and not like the change had been pushed on them can make a huge difference.”

Planning is crucial, and it takes a long time to get all the elements in place to satisfaction. Patel emphasises how important it is to take your time and how to structure that time. “Planning as early as possible is key to the success of any transformation project. Naturally, there should be some contingency time included in case of any unforeseen issues. The timeline should include pre-change, during and post-change activities with key milestones marked throughout each stage,” he says.

Matthews tells IT Pro there was a two to three year procurement process around his firm’s move, including time for evaluating different providers. “It was important for us to work on developing that relationship, as it can take a while to truly understand and define how we want to work, and determine how the partnership will pan out,” he explains.

Managing the learning curve

Once the switch has been made there will be learning points across the whole organisation. These won’t only be about working through new ways of doing things, requiring training and support for perhaps a considerable period. There might be bigger issues such as outages, or a realisation that additional technical tweaks are required that weren’t foreseen. It’s almost inevitable that there will be times when people can’t get their work done as a result.

It’s important to accept that there will be issues after the switch has been made and that it won’t be possible to anticipate them all. Instead, ensure the new contract allows for plenty of support. Matthews says there’s always an IT element that will go wrong and advises you need a service level agreement (SLA) that provides “the response you want from your provider in the timeframe you need”. In his case that meant a SLA that guarantees a response to any raised issue within 30 minutes.

Overall, switching to a new IT services provider takes time, planning and a degree of flexibility. The organisation that has a grip on its contracts, understands process and is able to handle the unexpected during and after transition is likely to have an easier time of making the change than the organisation that lacks these abilities.

A US dating site has pulled its website from Amazon's EC2 infrastructure citing "unpredictable datacentre issues".

Online dating-auction site, WhatsYourPrice.com, has decided to switch hosting providers, in light of Amazon's recent run of outages.

WhatsYourPrice.com founder and chief executive, Brandon Wade, said the online dating community is the least forgiving when it comes to downtime.

"Services focused on dating and relationships require constant accessibility," said Wade. "While you can watch a movie tomorrow if you miss it today, dating is all about the serendipity of meeting the right person at the right time. If an online dating service is not available, a user may lose the chance to meet his or her soul mate forever."

He said a previous outage, prior to the one reported by IT Pro this week, on 14 June flooded his dating website with complaints from thousands of members. Wade also claimed that repeated calls to Amazon's support team yielded no response.

Following Amazon's outage last weekend, which took Instagram and Pinterest offline, he decided to permanently move WhatsYourPrice.com to a Las Vegas-based hosting facility.

"Amazon's failure has negatively affected our website's reputation as a reliable online dating destination," said Wade, who was previously an IT infrastructure executive at General Electric.

"100 per cent uptime is a required SLA for anyone providing cloud computing services. Amazon's inability to provide such service levels is the main reason we have decided to quit using AWS EC2 altogether."

IT Pro contacted Amazon for a comment and had received no response at the time of publication.

Social networking site Twitter rolled back to a previous version of its website following an outage that left users unable to access the site.

In a blog post, Mazen Rawashdeh, vice president of engineering at Twitter, downplayed suggestions the site was hacked and said the outage was caused by a "cascading" bug.

This wasn't due to a hack or our new office or Euro 2012 or GIF avatars, as some have speculated.

However, at least one hacker group claimed responsibility for the downtime.

UgNazi, a relatively new group on the hacking scene and loosely affiliated with Lulzsec, said it launched a Distributed Denial of Service (DDoS) attack against Twitter over the company's support for the Cyber Intelligence Sharing and Protection Act.

Rawashdeh said the fault was discovered at 9am Pacific Time yesterday. "We discovered that Twitter was inaccessible for all web users, and mobile clients were not showing new Tweets," he said.

He said engineers began investigations into the downtime and found there was a "cascading bug in one of our infrastructure components."

"This wasn't due to a hack or our new office or Euro 2012 or GIF avatars, as some have speculated today," said Rawashdeh.

A cascading bug is one with an effect that isn't confined to a particular software element, he explained.

"One of the characteristics of such a bug is that it can have a significant impact on all users, worldwide, which was the case today.

"As soon as we discovered it, we took corrective actions, which included rolling back to a previous stable version of Twitter," he said.

He apologised for the outage and noted that in the past six months, Twitter had an up time of at least 99.96 per cent and often 99.99 per cent.

"This means that in an average 24-hour period, twitter.com has been stable and available to everyone for roughly 23 hours, 59 minutes and 40-ish seconds. Not today though," he joked.

Office 365 isn't a new version of the Office desktop suite; it's a cloud service offering the key server-based versions of desktop applications Exchange mail server with Forefront malware and spam protection, SharePoint document management (which can also power a public-facing Web site) and Lync Online for communications (presence, instant messaging and audio and video calls).

This is similar to the BPOS cloud service Microsoft has been running, but it has newer versions of the server-side software that are multi-tenant and (Microsoft claims) better suited to running as a cloud service. You also get online versions of Word, Excel, PowerPoint, OneNote and Outlook and some subscriptions even include the full Office Professional Plus suite. There's also an Office 365 marketplace for third-party tools that work with the service.

Office 365 is commonly seen as competing with Google Apps so we decided to look at them both.

Google Apps for Business includes Gmail with Postini spam and malware filtering and basic smartphone management, Calendar and Contacts, Google Docs (including spreadsheets and presentations), Chat, Groups mailing lists, Sites (for both intranet and public Web sites).

There's a control panel for managing users and what they can do with the Google Apps tools. You can also control user access to various other Google services like Picasa (which may get more important as Google combines personal and Google Apps accounts into a single account type) and add third party services from the Google Apps Marketplace.

Office 365 is commonly seen as competing with Google Apps so we decided to look at them both to see how similar the services really are and how they compare to each other.

Administration interface

As cloud services, you manage Google Apps and Office 365 online. Despite the simple layout, the Google Apps control panel is confusing until you learn where everything is. Options are scattered between Domain Settings, Settings, Advanced tools and the various links from the Dashboard tab which duplicate the Settings hierarchy. The Dashboard is also cluttered with adverts for optional tools in the Google App marketplace and adverts for new features.

The Google Apps admin page is cluttered with adverts for new features and third-party tools.

The Office 365 admin console is cleaner and better laid out, with a pane for switching between managing users, services and domain, clear explanations of what the main management tools are for next to the links to manage them. There are also handy shortcuts at the bottom of the window and links to relevant resources and community discussions.

By comparison, the Office 365 dashboard is clear and well laid out; you can see immediately what to do.

Google Apps has two levels of administration rights; the 'super admin' who has full access and admins to whom you can delegate some administration tasks. You can give different users a different mix of rights but you have to remember who can do what.

Office 365 has five named admin roles; you can give someone the rights to manage billing, passwords, users or services if you don't want them to have full admin rights. If you need more granularity, you can also set up administrator roles for Discovery Management, Records Management, UM (Unified Messaging) Management and other tasks in the Exchange Control Panel. It's more complex than Google Apps, but enterprises will welcome having the option.

Winner: Office 365. Microsoft's administration interface is not only better organised, it's also easier to handle when delegating management rights to others.

Setup and user management

There's a setup guide to get you started on Google Apps which walks you through things like verifying the domain you're using , creating user accounts and changing your MX records to point to Gmail (you need your own domain to use Google Apps). It's mostly clear and simple, but the duplicated instructions and sometimes circuitous inteface make setup a very fragmented experience. Setting up the Postini spam service tells you it may take up to an hour and again you have to change the MX records to redirect mail to the Postini service and configure some settings in Google Apps email by hand - all of which should be far more automated and suggests that Google has still not fully integrated the Postini acquisition with its platform.

Office 365's Forefront Online Protection for Exchange, SharePoint and Lync Online are running by default so all you have to do is create or migrate users. You only need to configure settings if you want to use an optional vanity domain, to get finer control or if you're integrating with on-premise servers. Thankfully the guides to doing this are clear and detailed.

You can create Office 365 users individually assigning admin rights and turning on services for them at the same time - or by importing a CSV file. You can also connect to an existing on-premise Exchange server and migrate users and mailboxes, or synchronise with your Active Directory to manage Office 365 users with roles and policies the same way you manage existing users (so you can delete a user in AD and they're removed from Exchange Online). You even get PowerShell cmdlets that let you configure Office 365 from the command line.

The Forefront rules and filters are very powerful but the interface is more complex.

To create Google Apps users you can set them up one by one in the control panel or import a CSV file - but most enterprises will use the Google Apps Directory Sync to get user details from AD or Lotus Domino, which the setup guide doesn't cover. This is a one-way sync and you have to leave the tool running on your local server and make changes to users in AD and propagate them up to Google Apps. To migrate mailboxes you have to run an Outlook sync utility individually and you can't migrate distribution lists, so you have to recreate them. It's initially confusing which tools you need for synchronising and migrating different information and settings to Google Apps, especially as the help pages often refer to old tools that have been replaced.

What Google Apps calls 'groups' are merely mailing lists. To control who gets which Google services you need to set up organization units. These cover both the core offerings like Gmail and the wide range of other Google tools whose terms and conditions your business will be deemed to have accepted if users from your business sign in with their Google Apps account - so this is mainly useful for disabling access to Picasa or YouTube if you don't want to accept those terms.

If business users sign into other Google services with their Google Apps account, the business is bound by the terms and conditions, so you can block this.

There's a separate option for whether users get access to functions and features from Google Labs, which could be a new option in Gmail or a tool like Google Moderator for managing a question and answer session at a company meeting (it's unclear what happens to these tools as Google recently announced that it is shutting down Google Labs). You can also use organization units to restrict which domains users can send email to, but you can't use them to control any other settings so it's nothing like as powerful as AD groups. You can't delete an organization without moving or deleting the users first, and deleting a user gives you the choice of deleting their documents or moving them to another user.

Both Microsoft and Google promise single sign-on. If you have Active Directory and AFDS 2, Office 365 users can use their Windows login to sign on to the local network (including any business apps you've integrated with that login) and to Office 365 services. Your Google Apps sign in gives you access to all the online Google services (including services that aren't part of Google Apps if the administrator allows this). It's possible to use a SAML bridge and the provisioning API to make that work with your in-house LDAP directory and local apps, but this is far from trivial to set up and it won't work with Google desktop applications.

Winner: Office 365. Microsoft's product is easier to set up and integrate into your company's existing infrastructure.

Mail server, malware and spam

Office 365 has a simple interface for basic admin options like managing passwords and security groups but you can also use the full Exchange Online interface. This is identical to the Web interface for Exchange Server, so it will be very familiar to Exchange admins. You get a comprehensive set of tools for setting up features like role-based access control, transport rules (such as adding disclaimers to external email) and reports to help you track down any problems along with auditing logs for compliance. If you don't need them then you can stick to the basics and be set up in minutes.

All the key email management features in Office 365 are available through a straightforward interface if you don't want to use the full Exchange interface.

Gmail has vastly fewer options because you don't get to control a mail server, although you do have some control over routing and mail gateway settings. The options are mostly on the level of setting up a vanity URL for users, choosing whether users can use Gmail Labs and chat or allowing Docs results to show up in a Gmail search. With Google looking after the mail server, most businesses won't need more admin options.

There are useful features in Google Apps that aren't turned on by default, and the interface is basic but clear.

Both Google Apps and Office 365 have a mailbox limit of 25GB. There's isn't an archiving option from Gmail, but with Office 365 you have a choice between third-party archiving services or a specific Office 365 plan with unlimited storage for email archiving.

Google Apps for business includes Postini Services for spam and malware detection, but you can't use it is you have multiple domains or if you want to use the Postini Discovery ediscovery and archiving service (in those cases you need to pay for Postini spam services separately). The Postini admin console is separate from the main Google Apps console and has tabs for viewing and deleting or approving messages detected as junk or viruses in the past three days, a week or for as long as it keeps records. The only option for virus blocking is whether you get email notifications that a mail has been quarantined, so you can check and release it if it's a false positive.

For spam you can whitelist individual senders, domains or mailing lists and block specific addresses or domains, set up inbound and outbound content filters for specific words, phrases or patterns and create attachment filters by size or type. You can also choose five levels of spam blocking, from lenient to very aggressive, and use category filters to put more emphasis on blocking explicit, 'racially insensitive' and financial spam. Oddly, IP whitelists to avoid spam filters go under the email settings pane, not in the Postini configuration page.

The Forefront admin console is also separate and has a very different interface from the rest of Office 365; it's powerful but also confusingly complicated for anything except checking quarantined email - we'd like to see this simplified for admins who don't already have Forefront expertise. What you get are the powerful Forefront Online Protection for Exchange (FOPE) tools; not just malware and spam filtering, but options to safelist specific IP addresses, options for auditing and tracing messages and extensive filtering rules for both inbound and outbound email. You can therefore write rules to stop your users emailing out confidential information such as credit card numbers. You can upload dictionary files when you have a lot of values to use in a filter and manage rules by type; there are a lot more options compared to Postini.

Neither service lets you add additional reputation services or real-time block lists, but both let you use SPF for your own reputation - only Google Apps supports DKIM so far.

Winner:Tie. There's no outright winner in this category. Gmail is perfect if you want to get up and running as quickly as possible, while Office 365 provides fine grained controls and capabilities that will suit particularly fastidious organisations.

Mobile management

With Google Apps for Business, you can manage Android devices (as long as they run Android 2.2 or later). You can set a policy that enforces a password of a particular strength and wipe lost devices and users can remotely locate or lock their phone or make it ring. You have to manage rolling out device security as it requires an app users download from Android Marketplace, but turning on device security stops them using Android Marketplace until the app is installed (there's a direct link to get around the chicken and egg problem here).

There's also a connector to allow you to manage BlackBerry users of Google Apps from a BlackBerry Enterprise Server, and options for applying password and other device policies to smartphones using Google Sync or Exchange ActiveSync, which can end up as a confusing mix of management options.

Fine control of smartphone security in an interface that will be familiar to any Exchange administrator.

Office 365 has a more unified and comprehensive approach. Exchange Online gives you the same mobile device management as Exchange Server using ActiveSync Policies which work to some extent on virtually all smartphones including Android, iPhone. BlackBerry and Symbian as well as Windows Mobile and Windows Phone. You can enforce strong passwords and encryption, control individual device features (like Bluetooth), configure sync options like whether attachments can be downloaded on a phone and wipe devices automatically if the password is wrong too many times. You can also block or quarantine specific mobile devices from connecting. Users can even block or wipe their own phones.

Winner: Office 365's unified and comprehensive approach to smartphone management makes it the clear winner here.

Document management

Google Docs has no equivalent to SharePoint Online. Sites is a nice simple tool for creating internal or external Web pages and with Google Docs, you can control whether users can publish or share documents outside the business and whether documents default to being private or public. Otherwise sharing is an ad hoc thing that users control.

SharePoint Online combines workflow, document management and Web publishing and it looks professional straight away.

SharePoint Online combines Web page authoring for external sites with a full document management tool with libraries, lists, templates, discussion tools, shared calendars, RSS feeds, workflow, check in and check out options and version control plus powerful search options. Your Team Site includes pages for every user where they can blog, share links and documents or access their files on the move. Taking advantage of all the options is more complex but it's also far more powerful.

Winner: Office 365 has much more capable sharing features, but these are correspondingly more complicated to manage. If you need them though, then it's worth bearing with.

Chat and talk

Google Chat is the same simple but powerful tool available to the public; users can see presence for Google Apps contacts inside Gmail and start a text, voice or video chat from there once they've downloaded the plug-in. Alternatively they can use the Windows Google Talk software for text and voice chat or file transfer. Management is minimal; you can block chat outside the organisation or just warn users but you can't block file transfers.

Microsoft's Lync Online is more powerful. The extensive management options let you choose whether users can transfer files, make audio or video calls and talk to people outside the business or just colleagues.

Users can see each other's presence and status in Outlook and Outlook Web Access (including information from someone's Exchange calendar), and in any Office app where you're collaborating. It's possible to start a chat, voice or video call from there or from the Lync client. Microsoft is also promising Lync clients from a range of smartphones, offering IM first and voice features later. If you have an in-house PBX you can also set up unified messaging (like dialling phone calls from Outlook) and integrate voicemail with Exchange Online although we weren't able to test this.

Lync Online automatically federates with Windows Messenger and AOL for instant messaging.

Lync Online automatically federates with Windows Messenger and AOL for instant messaging. It can also federate with on-premise Lync servers if permitted by the server admin.

Google Apps can federate with any XMPP service, but to make that work you have to edit the SRV record in your domain by hand (or ask your domain hoster to do it for you), and you then get federation with all the services Google is connected to - you don't get to choose which are allowed or blocked. Similarly, you can allow users to chat with any Gmail or Google Apps user or block them all; you can't pick and choose which Google Apps-using companies they can communicate with and you can't block or allow chat access for specific users (individually or by groups).

Lync Online also incorporates the features of LiveMeeting; you can switch from an IM chat to an online meeting with up to 250 people with audio, video and Web conferencing, and you can schedule meetings in advance through Outlook. If you want to let people phone in to a meeting without needing Lync (customers for example), you can buy an audio conferencing service for Lync Online from BT.

Winner: Office 365. Google App's chat and messaging features are fine for most users, but for more fine-grained controls, Office 365 is better.

Online apps

Online apps like Google Docs are primitive compared to the richness of the full Office suite. In general, the features of the Office Web Apps and Google Docs are broadly similar, but while many like the sparse interface of Google Docs for its simplicity, the Office Web Apps tend to have the edge in sophistication.

Create a PowerPoint presentation in the Office Web Apps and you get good-looking themes and images you place are automatically sized to fit; a Google Docs presentation starts out in plain black and white and the designs aren't as appealing.

The Office 365 Outlook Web App has good self-service features for users (and you only see the admin links if you're an administrator).

Office Web Apps make inserting images from your hard drive the same simple experience it is in a local app. Google Docs gives you a wider choice for inserting images from a URL or a Google image search in a document, but it's a completely different dialog box in a presentation where inserting an image has fewer options and is a clunkier experience. The mismatch of features between different document types in Google Docs is more extreme and more jarring than in the Office Web Apps.

Sharing is better integrated in Google Docs, with a big blue Share button on the page that opens a popup dialog box. The Office Web Apps make you save the document and take you away from the editor to choose who to share it with, and take you back to viewing but not editing the document. This is because Microsoft assumes that you won't share a document until you've finished working on it. Updates appear live in Google Docs; this also happens in the OneNote Web App but the other Microsoft Web apps make you save your own changes to see edits by other users.

There are many features in both Outlook and Outlook Web that are missing from Gmail from macros to Quick Steps. Gmail equivalents tend to have fewer features which some users prefer because they're simpler. Gmail's stars, labels and priority buttons let you do much the same things as Outlook's flags, categories and folders with the advantage that a message can have multiple labels instead of being in only one folder.

You can turn an email into a Gmail task and then make a reminder, although this isn't quite as immediate as setting a follow-up flag for a specific day directly on an email. Filters the Gmail equivalent of Outlook rules have far fewer actions; in Outlook you can play sounds, send an automatic reply or even print a message that matches a rule. Gmail does include all the mostly commonly used ones though such as filing, forwarding and deleting messages.

Google Apps for Business Gmail users finally get the option to request read receipts, but these have to be enabled by the administrator and Gmail doesn't respond to delivery or read receipt requests in emails sent from Exchange. Gmail only shows the request when you close the message (Outlook shows it when you open the message) and you have to decide for each message as Gmail doesn't have Outlook's don't ask me again' checkbox. Even more irritating; if you don't want to send the receipt the button you click is marked not now' and Gmail will ask you again every time you read the message.

Apart from creating resources using Google's complex naming structure, you have only a few controls for calendar sharing.

Google Calendar can include shared resources - like rooms and projectors that need booking - which you create by typing in the details one at a time. Oddly there isn't a drop-down picklist to ensure the resources are given consistent names or a wizard to help with the complex naming conventions Google suggests, so you could end up with six conference rooms and one meeting room if you're not careful. If you follow the convention suggested, all resources that start with the same three letters will be grouped into a hierarchy but you can't do this manually.

Exchange Online has templates for creating resources like rooms (as well as equipment that isn't in a fixed location); you can even say which users can reserve rooms without permission and how often.

The Google Calendar features for end users aren't quite as powerful or complex as in Outlook, but you get the important options like overlaid calendars and recurring appointments. The Quick add tool that lets you type in a sentence, including the day and date of what you need to do, which then sets an event on the right day at the right time is a phenomenal time saver.

Winner: Tie. The Microsoft Web Apps for crediting documents are more sophisticated than Google's equivalents, but Google Docs has better sharing and collaboration features. Exchange Online has a plethorea of configurable options, but many organisations won't need these and may prefer Google's less feature-packed but also less cluttered approach.

Office and working offline

Depending on which plan you sign up for Office 365 includes download rights for the professional version of Office 2010, which includes OneNote, Publisher and Access as well as the usual Word, Excel and PowerPoint. You can load and save documents from all of them into the SharePoint Online site included in Office 365 and use the online collaboration features to edit documents at the same time in the main apps.

Depending on which plan you sign up for Office 365 includes download rights for the professional version of Office 2010.

This is a bargain; you get the full power of Office and the back-end servers that enable all the features, from using Information Rights Management to control who can distribute a file to asking people to update a database by replying to email. One great feature for businesses; you can host PowerPoint presentations online and present to a group of people on the Web, letting them ask questions and make comments ideal for training or sales pitches.

Also available are the publicly accessible Office Web Apps; Word, Excel, PowerPoint and OneNote all but PowerPoint let multiple users edit the same document at the same time. SharePoint synchronisation neatly takes care of making documents available offline as well as accessing them from anywhere online.

Although offline access to Gmail and Google Docs (without the deprecated Gears plugin) is still only available to Google employees, Google recognises that offline document access matters. You can run software to sync Outlook with Gmail, Calendar and Contacts, and to move Outlook Notes to Google Docs (though they're read-only, it doesn't sync notes filed in folders - and if you use Outlook on multiple PCs you have to run the tool on all of them because categories, follow-up flags and other settings don't sync fully otherwise).

There's a connector toolbar for Office that lets you sync documents to Google Docs; the latest release fixes many of the problems in the first version, but it's not as polished as the SharePoint integration and converting files into Google Docs for editing online doesn't preserve all document features (the same thing happens when you open an email attachment in Google Docs). You can't edit watermarks, smart art, charts or footers in Office Web Apps, but you can see them in the read-only viewer and they're preserved in the document so you get them back when you open it back in Office. Google Docs doesn't show those details and doesn't keep them if you edit the document. Even fonts and line spacing can change when you move Office documents in and out of Google Docs.

Winner: Office 365. Microsoft's offline support is far from polished, essentially being dependent on SharePoint and subscription access to the full Office suite, but this is also, unsurprisingly, far more capable than Google's cumbersome and crude offline tools.

Service levels and support

The Google Apps dashboard repeatedly told us that there might be a problem with an unspecified Google Apps service; whenever we clicked through to the dashboard all the services showed as having no issues, but seeing the warning virtually all the time was concerning. Office 365 has a similar service health dashboard; neither service had any major outages or failures while we were testing them, but Office 365 didn't keep warning us of non-existent problems.

Despite frequent warnings about a problem, Google Apps didn't record any disruptions to the service.

Both services promise 99.9% availability. Google Apps measures this on a monthly basis with a credit of three days of service if the SLA is not met in a month; Office 365 credits 25%, 50% or 100% of the service cost if the SLA falls below 99.9%, 99% and 95% respectively.

Google Apps has no planned downtime; Office365 does schedule maintenance when usage is likely to be low for example Lync might be unavailable for five minutes at 1am on a Saturday morning and dates and times are listed five days in advance in the support area.

Support is definitely better with Office 365. Support is requested using the admin console and your requests are managed there, but 24-7 phone support is also available with response times from 15 minutes to four hours depending on the severity.

Issues with Office 365 can be broken down by exactly which part of the service is affected.

Google Apps also has 24-7 phone support but only for critical problems that involve more than half your users and affect the Google Apps Web services. If the problem was with mobile emails you'd be stuck with email support, which doesn't cover weekends.

Winner: Office 365, but only just. It's tough to judge how reliable a cloud service is, but Microsoft's technical support has better availability which is reassuring.

Verdict

Google Apps has a flat price of 33 per user per year; Office 365 has a range of prices from 6.50 to 17.75 a month, depending on whether you want Office, Office Web Apps, SharePoint, Lync or archiving it can be more expensive but you can choose what services you want to pay for and there are discounts for volume pricing (including transferring existing Exchange and SharePoint server licences to Office 365).

Google Apps is in a constant state of flux.

Google Apps is in a constant state of flux; the whole service is migrating to a new platform, there are two versions of the control panel available, there are options to give users access to previews of new interfaces and features from Google Labs which itself is going away, with no indication of what happens to the features it provides and new features like return receipts arrive periodically. Getting continuous, instant improvements is one of the benefits of cloud services, but if you're managing the service and supporting users you might prefer Microsoft's approach where updates come at regular intervals and you can choose whether to adopt them immediately or by a specific date.

That underlines one key difference between the two services that has little to do with features; Office 365 has the professional feel of a service planned in advance and designed for administrators; Google Apps has the feel of a service that has grown by leaps and bounds, but sometimes in a rather haphazard way that's not always consistent.

In the end, the two services are both powerful but they suit different audiences.

In the end, the two services are both powerful but they suit different audiences. If your business already uses Microsoft tools, Office 365 is the logical progression, giving you server workloads that integrate with and make the most of your existing investments. It's a comprehensive, powerful, end-to-end cloud platform for business that doesn't make you do everything online, which many businesses find a step too far. You can have all the power of Exchange and SharePoint without the bother of configuring and running them.

If you need a mix of on-premise and cloud services, having to manage both Active Directory and the Google Apps control panel is more work than being able to do everything through System Center. Google Apps is a better fit for businesses starting from scratch online with no legacy systems who can benefit from the simplicity without having to keep the service in sync with on-premise tools, but it has definite limits.

MICROSOFT OFFICE 365 SYSTEM REQUIREMENTS Operating system: Windows XP SP3 or later; MacOS X Leopard 10.5 or later; Windows Server 2003 or later Office client: Office 2007 SP2; Office 2008 or later; Lync 2010 Administration and Office Web Apps: a modern web browser Active Directory-based features: single forest GOOGLE APPS SYSTEM REQUIREMENTS Modern web browser

Google has adjusted the service level agreement (SLA) of its application offering to remove any scheduled downtime.

Google Apps, which includes Gmail, IM and Calendar, previously had a clause enabling Google to take the service down for scheduled maintenance.

The company has now removed this clause and, although it admits unscheduled downtime will always be a possibility, it hopes to achieve ambitious uptime of 99.99 per cent.

In a blog post late last week, Matthew Glotzbach, Google's enterprise product management director, said: "Unlike most providers, we don't plan for our users to be down, even when we're upgrading our services or maintaining our systems. For that reason, we're removing the SLA clause that allows for scheduled downtime."

"Going forward, all downtime will be counted and applied towards the customer's SLA. We are the first major cloud provider to eliminate maintenance windows from their service level agreement."

He also confirmed any unscheduled downtime would be counted.

"Previously, a period of less than ten minutes was not included," Glotzbatch added. "We believe any instance that causes our users to experience downtime should be avoided period."

One of the reasons companies have cited for being nervous about the move to a public cloud model was unsuspected downtime, leaving them unable to access mission critical applications.

However, Glotzbath claimed the average of seven minutes downtime each month for Gmail in 2010 was better than many on-premise alternatives.

He quoted research from the Radicati Group, which claimed average downtime for on-premise email was 3.8 hours per month, making Gmail 32 times more reliable than the average email system.