He cited research by the Meta Group, showing that more than half of legacy systems specialists are over 50 years old and nearing retirement, and it is increasingly difficult to find young replacement workers with mainframe skills or who understand mainframe-related datacentre disciplines.
This mass retirement phenomenon is affecting many industries, and has resulted partly from fluctuating economic conditions. Post-war baby-boomers are approaching their mid-50s with healthy pension packages, and many are considering retiring earlier than their 35- 45-year-old counterparts.
What makes IT different is that this band of employees takes with it a vast amount of mainframe expertise and niche skills, leaving behind a void in the skills needed to run our most business-critical systems.
None of this matters - if your mainframe is maintenance-free and fully automated, and your applications never need to be tuned or integrated with other systems - few are.
For some years - since the downsizing obsession of the early 1990s - there has been a misapprehension within the industry that mainframe technology is gradually winding down, to be replaced by more dynamic Unix, PC and network-based solutions. For almost a decade customers were encouraged to encapsulate their back-end S/390-based systems, label them legacy and exploit newer applications on other platforms.
Responding to the change in mood, and the consequent shift in demand, programmers and staff with a mainframe background have either started to retrain in more fashionable technologies or made their excuses and moved into tropical fish farming (returning to IT only briefly a few years ago to help solve the Y2K problem).
The swing of the pendulum back in favour of large centralised servers has coincided with the realisation that natural wastage is reducing the workforce.
Afcom members at the conference said they have been putting new programmes in place to try to encourage mainframers to expand their knowledge in key strategic areas, such as Web/host integration, while persuading younger employees that having z/OS and Cics on your CV is not the kiss of death.
I suspect that European datacentres are not yet so concerned and we certainly have fewer mainframe installations on the scale of those represented at Afcom, but we do need to be aware of the demographic trends.
Mike Kerford-Byrnes, a UK mainframe systems specialist whose Y2K re-engineering company, Millennia III, pulled a small army of Cobol experts out of semi-retirement a few years back to confront that crisis. He is looking closely at future staffing issues for some large clients.
If Y2K taught us anything, he says, it is that we need to automate as much of the legacy systems function as we can - not just operations but Cobol support and application maintenance.
It is ironic that, at a time when the IBM zSeries (S/390) is looking more attractive, cost-effective, and powerful than it has done for years, chief information officers at mainframe sites may find their options limited by their ability to find the right people for the job. Some may find outsourcing the only option.
Mark Lillycrop is chief executive of IT analyst company Arcati, and represents Afcom and the Data Center Institute in Europe.