There are two kinds of IT managers reading this right now.
The first one already knows the problem. Their AS/400 person retired last quarter, last month, or last week. The system is still running. The backlog of things nobody knows how to touch is growing. And every time something unusual happens, there is a moment of quiet panic before someone figures it out.
The second one can see it coming. Their AS/400 person is 58, maybe 62. Has been with the company for 25 years. Knows the system better than anyone, possibly better than IBM. And when that person walks out the door, they are taking decades of undocumented knowledge with them.
Both of these situations have the same problem at their center. The AS/400 iSeries was never designed to be handed off. The people who built expertise on it learned entirely on the job, inside the system, over years. By 2030, nearly all available RPG talent will have retired. And young programmers have not, and will not, enter the RPG pipeline.
That is not a prediction. It is already playing out across hundreds of businesses running IBM i today.
More than 150,000 companies worldwide use the IBM iSeries platform. Most of them are facing the same staffing cliff. The difference between the ones that handle it well and the ones that get hurt is how early they act and what they put in place before the knowledge gap becomes a crisis.
What You Are Really Losing When Your AS/400 Person Leaves
The system itself is not the problem. The AS/400 iSeries is remarkably stable. You can run a program created for the AS/400 in 1988 on a Power Systems server today with little or no changes. IBM continues to maintain and update the platform. The hardware is not going anywhere.
What leaves with your retiring expert is something harder to replace than the system itself.
It is the institutional knowledge. The undocumented customizations built over fifteen years. The job scheduler that runs every morning and the specific sequence it has to follow. The reason the accounts payable module was modified in 2009 and what breaks if you touch it the wrong way. The vendor who handles the annual OS upgrade and the two things you have to remind them about every time. None of that is in a manual. It exists in one person’s head.
When AS/400 veterans retire, all their knowledge and expertise go right out the door with them. For businesses where the AS/400 is running mission-critical operations, that exit can expose gaps that were invisible while the expert was still in the building.
AS/400 systems knowledge can only be learned on-site, inside the system. It cannot be understood outside it. That is why replacement hiring is so difficult. You cannot hire a junior developer, point them at documentation, and expect them to be productive in six months. The platform simply does not work that way.
The Two Situations and What Each One Actually Needs
If your expert has already left
The immediate priority is stability. The system is running, but you are in an exposed position. Any incident that would normally have been resolved in two hours by someone who knows the environment will now take significantly longer, or require outside help on an emergency basis, which is expensive and slow.
The first thing most IT managers in this situation reach for is a break-fix support arrangement. They call someone when something breaks. This works until it does not, and the moment it does not is usually the worst possible time, during a period close, a system update, or a compliance audit.
What the post-retirement situation actually calls for is proactive AS/400 iSeries support that covers the environment continuously, not just when something goes wrong. That means someone who knows the system is monitoring it, maintaining it, and available when you need them, without you having to find and brief a new person every time something happens.
The questions to ask any AS/400 managed services provider in this situation are specific. Do they have RPG and CL expertise on staff or are they routing AS/400 tickets to a general support team? Can they take on an environment they did not build? How do they handle undocumented customizations? What does their incident response time actually look like in practice? A provider who ticks the box on IBM i but primarily works on modern platforms is not the same as one for whom AS/400 iSeries support is a core practice.
If your expert is still there but leaving soon
This is the better position to be in, but only if you use the time. The window between now and their retirement date is the most valuable period you have. It will not come back.
The most important thing you can do in this window is structured knowledge transfer. Not a handover document that gets written in the last two weeks before someone leaves, but a deliberate process of capturing what the system actually does, how it is configured, what the dependencies are, and what the known issues are. This is hard to do well without an outside party to facilitate it, because the person leaving often does not know what they know. Much of their expertise is tacit and only surfaces when someone asks the right questions.
The second priority in this window is an honest audit of the environment. Which parts of the AS/400 setup are well documented and stable? Which parts are fragile, undocumented, or dependent on one person’s understanding? What would break first if that person were not there? That audit is much easier to conduct while the expert is still available to answer questions than after they have gone.
Getting an AS/400 managed services provider involved before the retirement, rather than after, means the knowledge transfer happens into a team that can actually absorb and act on it. They learn the environment from your expert, not from incident tickets.
What AS/400 Managed Services Actually Covers?
There is a lot of variation in what different providers mean when they say AS/400 managed services. It is worth being specific about what you should expect.
At a minimum, a managed services arrangement for an IBM iSeries environment should cover system monitoring and health checks so you know about problems before users do. It should cover OS and security patch management, because an AS/400 that is not being updated is accumulating security risk quietly. It should cover performance tuning, backup and recovery management, and job scheduler maintenance.
Beyond the basics, the right provider should be able to handle application support for your RPG, CL, and SQL-based applications. This is where many general managed services providers fall short. Supporting the infrastructure is one thing. Understanding the applications running on it well enough to troubleshoot, modify, and maintain them is a different capability.
The 2024 IBM i Marketplace Survey found that 72% of IBM i users now cite modernization as a top concern, up from just 51% in 2021. A good managed services provider should also be able to have an honest conversation about modernization options without pushing a migration agenda. For many businesses, AS/400 iSeries support is the right answer right now, not because the platform is perfect, but because the risk and cost of migration outweighs the benefit at this point in time. A provider who understands this will help you stabilize and run the environment well. A provider who only sees AS/400 as a migration opportunity will not serve you well.
What to Do Right Now Depending on Where You Are?
If your expert has already left, the most urgent thing is to get a qualified AS/400 iSeries support partner engaged before your first major incident rather than during it. Emergency support is available but it is significantly more expensive, slower, and relies on people learning your environment under pressure. The sooner you establish a managed relationship, the sooner your environment has someone watching it who knows what they are looking at.
If your expert is still there, the most urgent thing is to start the knowledge capture process now. Not in three months. Not when the retirement date is confirmed. You should start it right Now. Set aside time every week for structured conversations about the environment. Record them. Bring in a managed services provider to be part of that process so the knowledge lands somewhere useful.
Finding skilled IBM i professionals is becoming increasingly difficult as younger developers gravitate toward modern platforms. That scarcity is not improving. The businesses that act early are the ones that maintain continuity. The ones that wait are the ones who discover on a Tuesday morning that nobody knows how to restart a failed job queue, and the system that runs their entire operation is waiting.
The AS/400 has been running your business reliably for years. The question is not whether the platform can keep doing that. The question is whether you have the right support structure or partner in place when the person who has been making that happen is no longer there.
For more insights, read our article on: What is AS/400 Warehouse Management System and How Does It Work?
