What's the biggest blocker for legacy large companies IT to switch to cloud technologies?

Here is a recent question in an online forum. My response follows.

A few years ago, a new CIO took over our organization, a multinational supply-chain company and had a clear cloud-first mandate. The team was able to get the stakeholders aligned on a cloud (SaaS, PaaS, IaaS) based portfolio strategy.
I led an extensive assessment of the application portfolio, reviewing the different dimensions of individual platforms and capabilities.

1. Some applications were clearly SaaS candidates since the vendor offerings had matured
2. A few were good candidates for PaaS, especially where the organization had the capability to manage the service
3. Due to network, latency, data volume, legal and other constraints, some applications would have to remain in IaaS (Private, Virtual Private Cloud)
4. Some legacy applications had clearly not been designed to be virtualized and would not benefit from a move to the cloud (even to IaaS). These were running on old/proprietary hardware infrastructure and would have to be redesigned (and not just ‘migrated’)

If we set aside politics, turf wars, legal and privacy constraints, one will still encounter genuine technical constraints (#4 above) that prevent an application move to the cloud.

One might argue that even those applications can be ‘migrated’ to a cloud with some refactoring. However, the cost of such migration may not justify the benefit. Doing so merely to satisfy CxOs ego to say ‘we are entirely on the cloud’ is bound to be counterproductive. 

Microsoft 365 on the cloud: The Future is Past

With rollout of Microsoft 365, Redmond has finally got an answer to Cloud Computing, at least in the commodity applications space.

So what’s new? Not much if you, like me, have also been using Microsoft’ hotmail account – email over cloud - for over a decade. Every large Software vendor aspires to a share of the next big thing and for now it is the cloud. Same goes for every IT professional, self included, who wishes to keep on top of the latest: one just can’t stay away from the hype over cloud computing.

Much of the research surveys point to how commodity applications from Apple, Google and Microsoft are going to change our lives. Surveys also highlight the fact that few IT executives expect their organizations to select a public cloud over a private cloud.

As regards commodity applications, they are not as new as they are being touted to be. I guess the change is already here:
• email on the cloud – since mid 1990s : over 15 years old
• WebEx, instant messenger services on the cloud – since late 1990s – over a decade
• SalesForce case studies on cloud computing – since early 2000 – nearly a decade
• Online learning tools – since mid 1990s – over 15 years
• Social media tools – evolving for the past decade
• Music and video on the cloud – services evolving for the past decade. Remember the hype when google bought out youtube?
• Documents on the web? Openoffice, OpenDocs etc since late 1990s.

A few blogs on the topic
• Cloud Computing: The Future is Past
• For Microsoft, Is The Cloud A Threat – Or Their Secret Weapon?
• My Musing on Cloud Computing, Sourcing and Offshoring
• Memo to Microsoft: It’s Time for Windows 365