Microsoft has failed to explain to corporate customers the repercussions of the twice-a-year schedule that will deliver Windows 10 upgrades each March and September, an analyst has argued.
There are too many uncertainties about the upgrade schedule, a critical part of Microsoft's "Windows as a service" model, said Michael Cherry, analyst with Directions on Microsoft.
"Customers shouldn't have to figure this out," Cherry said, referring to unanswered questions he had after participating in an online "Ask Me Anything"-style discussion that Microsoft hosted two weeks ago.
"We shouldn't even be having this conversation about, 'Maybe they mean this, or maybe they mean that.' They should have told us, 'Here's how it works, here's the documentation, here's the TechNet article, here's everything.'"
Cherry aimed his criticism at Microsoft's announcement last month that Windows 10 feature upgrades would release each March and September, and that each upgrade would be supported for 18 months.
His first complaint was that Microsoft presented the new setup as a done deal that customers -- including enterprises that want consistency -- could bank on.
But the company has not yet demonstrated it can hit an every-six-month schedule; the three upgrades released thus far came at intervals of four months, seven months and 11 months.
Cherry questioned the company's ability to fulfill its promise.
"We need to see consistency that they're able to accomplish this," he cautioned. "For now I say that this is aspirational, not policy. They hope to do this [every March and September]. But if they don't, they don't. If it's June, it's June. Or April."
The problem is that if Microsoft doesn't make a deadline, the delay would have a domino effect.
"What happens if they slip too far?" Cherry asked. "If Microsoft misses [a release] by six months, then they've knocked six months off the time before you have to upgrade to the next."
Microsoft has said nothing about what it would do in such a case. And that's a problem, said Cherry. If Microsoft pushes back the following releases, for example, the March-and-September cadence collapses.
But if Microsoft simply resumes the tempo with the next slated release, the delay either eats into a version's support lifetime or throws off the schedule.
One likely consequence? Microsoft's promise that customers will be able to skip a Windows 10 features upgrade may be in deep trouble.
Under ideal conditions, enterprises have only a two-month migration window if they pass an intervening upgrade. Any delay in the schedule would make upgrade skipping impossible, forcing businesses to deal with each refresh, something Cherry predicted would happen.
In fact, businesses don't really get a full 18 months out of any one Windows 10 version. The first four of the 18 is, and will continue to be, designated as relatively unpolished, fit for consumers -- who act as Microsoft's unpaid testers -- but not for corporate use.
Only after Microsoft promotes the version as suitable for widespread company deployment by marking it as "Current Branch for Business," or starting this fall, as "Semi-Annual Channel (Broad)," are enterprises to roll it out to workers. So the maximum amount of support to businesses for a given version: 14 months.
Even companies that jump on the uneven code -- what Microsoft now calls "Current Branch" but will rename "Semi-Annual Channel (Pilot) in September -- may not get 18 months on a release.
"Microsoft told us, 'Don't install it yet,'" Cherry said of version 1703, the feature upgrade that launched April 11.
He was referring to Microsoft's message, actually aimed at consumers, that they wait for Microsoft to offer the refresh rather than grabbing it immediately.
Microsoft delivers feature upgrades in stages, first to a small set of users whose systems will have the greatest chance of successfully completing the upgrade. The company expands the upgrade pool as it fixes problems reported by others until it opens the throttle.
Last year it took three months to ship 2016's one upgrade to more than 80 per cent of those running Windows 10, meaning that many had 15 or fewer months of support.
"The 18-month count-down starts on the first day," Cherry said about an upgrade's release. "But if you're not at the front of the testing line, you don't get 18 months. So should I speed up my timeline to get [the full] 18?"
If Microsoft promises that support lifecycle, Cherry argued, enterprise users should get it. "The clock really shouldn't start until [a version] is fully deployable without concerns," he said.
That would be when Microsoft reported a build as business ready, and promoted it to the Current Branch for Business, or when that label wears out, Semi-Annual Channel (Broad).
Under that alternate scheme, Windows 10 upgrades would be supported for a total of 22 months, not 18, as each refresh would still require some testing, presumably the same four months as today, with consumers before it's rated ready for enterprise deployment.
Such a change may seem minor, but it would mean -- assuming Microsoft continues to issue feature upgrades at six-month intervals -- that the firm would be required to support not two, but three CBB/Semi-Annual Channel (Broad) releases simultaneously, and for a four-month span when the latest was in consumers' hands, four releases.
To know when support lapses for each given Windows 10 release, enterprises must construct visual aids, Cherry argued. "You have to actually figure out your support," he complained. "You almost have to build a matrix."
Microsoft has provided nothing like that. Previously, that was understandable because Windows 10 releases were on a more flexible schedule.
But under the twice-yearly plan, releases and support are supposed to be consistent so that enterprises can plan; some kind of chart should have been forthcoming from Microsoft.
"It's frustrating," concluded Cherry, speaking of Microsoft's silence on scheduling topics. "Our clients come to us for answers, and we don't have them."