Beyond COBOL: Is PL/I Modernization Your Blind Spot?

00:00:00 Becky

Hi and welcome to this episode of the Heirloom Modcast, a podcast series all about mainframe modernization. I'm Becky Etheridge, Chief Partner Officer for Heirloom Computing. Today's Modcast episode is Beyond COBOL, is your PL/I your modernization blind spot?

But before we delve into that, let me quickly introduce you to Heirloom Computing. So we are a software company and we partner with clients and global system integrators to migrate mainframe workloads to modern stacks that are service agnostic for execution on any cloud, on-premise or indeed on the mainframe. So with us today is Heirloom Chief Technology Officer Graham Cunningham and we are delighted to welcome back to the Modcast series our very special guest ISG Distinguished Analyst Pedro Pedro Macchio.

So Graham and Pedro I know you both have a lot to talk about today, so let me hand it over to you in the first instance Pedro for your initial thoughts on the legacy language challenges in the marketplace today and in particular PL/1.

00:01:10 Pedro

Thank you Becky and before I start congratulations once again for Heirloom's leadership position in the ISG 2025 ProviderLens Mainframe Modernization Software Quadrant report. It's outstanding that many years you've been hosting this position. Working on the ProviderLens report allowed me to track with clients and get some insight into the challenges faced by IT leaders around mainframe modernization and legacy languages like PL/I.

PL/1 is a key language in the mainframe environment with almost every mainframe having some kind of application written in PL/I because it can sometimes optimize mainframe resources. The issue today is that many companies can convert COBOL to modern languages but very few can rewrite or convert PL/I. Even when clients find a tool to convert PL/1 they struggle to find programmers to work with it.

Our surveys shows that less than a third of mainframe modernization tools out there can convert PL/I. However from a small sample of system integrators that use these tools with their clients they report over 12,000 COBOL programmers on their staff and the same system integrators report that only 600 programmers can manage PL/1. That's a huge difference.

So if you think hiring and retaining COBOL programmers is hard imagine how hard it is to find a PL/I programmer to work for you. In other words only five percent of the old retiring and experienced programmers can deal with PL/1. What's interesting is that Heirloom, I understand that Graham, that you can offer both COBOL and PL/I migration paths.

Is that true?

00:03:10 Graham

Yes it is. I mean first thanks Pedro for a great overview of the market. It really aligns with what we've been seeing.

You know PL/1 knowledge is definitely at a premium. Heirloom offers both COBOL and PL/I modernization products and they're both driven by our unique transpiler technology. We first came to the market with our COBOL solution over a decade ago.

It's actually nearly 15 years ago and it was real customer demand in the past five years that has led us to develop our PL/1 product. Since then we've seen a real uptick in PL/I migration requirements across many sectors but in particularly the insurance and manufacturing space. You know there's many really heavy PL/1 workloads that sit alongside COBOL applications so now we're able to offer our clients the ability to migrate and modernize all their core mainframe workloads and through our partner ecosystem we can also address other 4GLs.

So our clients aren't faced with multiple vendor relationships. They can simply trust Heirloom and we can help them navigate through their modernization journey.

00:04:31 Pedro

There are many options I guess but what are the main differences between PL/I and COBOL that people should understand for the new people that have never worked with COBOL and PL/1? Perhaps they think it's the same. What do they need to know about it?

00:04:50 Graham

Well I mean in terms of business they are the same. You know their languages run on the same mainframe but PL/I is a much more systems level language. It's got sophisticated built-in capabilities for memory management and pointer manipulation and it makes linked lists and other system level algorithms much, much simpler to implement.

In COBOL you can do that kind of work but it's difficult so you often see complex algorithms implemented in PL/1 that would just be really onerous to implement in COBOL. We have one client Arek Oy in Finland that had their multi-decade compound interest calculations for pensions written in PL/I. They were our first PL/1 compiler customer and they are a reference client.

One other aspect of PL/I that's different to COBOL is PL/1 has a macro preprocessor. We think we are the only vendor to offer a full implementation of this key piece of PL/I. Many clients have used the macro preprocessor extensively and some have even created almost their own domain specific languages and so being able to handle this preprocessor macro capability is an enormous advantage to us.

But what it's important to realize is that the underlying mainframe systems are the same for PL/1 and COBOL and this means that with the same runtime technology for PL/I or for COBOL we have the same runtime technology for PL/1 and these subsystems are things like FileIO, TransactionManagers, KXIMS, RACF etc. and we've had this COBOL product for 15 years now. So although our PL/I compile is relatively new, you know five years old, is new in mainframe terms, the runtime it uses is rock solid and battle hardened and used in production for many years.

00:07:00 Pedro

So and in general what are the benefits of using Heirloom for migration? I think that you mentioned one which is saying that you're the only one to do it but in particular for PL/1 workloads what's the general benefits of using Heirloom?

00:07:18 Graham

Well I'm sure you hear the same buzzwords from all vendors. Everybody talks about going fast and lowering risk, offering flexibility but honestly Heirloom has actually built all that into our tooling because we understand that putting our customer in control is the safest and fastest path to success. So you know IT leaders are faced with many different challenges.

Some are in get off the mainframe yesterday scenario, driven purely by costs or business pressures. So they'll be looking at re-platform solutions. Some will be wrestling with that skills crisis you mentioned earlier and will be considering a refactor approach.

But here's the thing, most clients don't want to be boxed in right. They want to future-proof their modernization strategy and that doesn't involve a single path or the prospect of juggling multiple vendors to get to where they need to be. Heirloom's kind of superpower is it eliminates that complexity entirely.

Our solution flexes changes to give customers exactly the right mix of both re-platform and refactor capabilities at any stage of their journey. So our customers decide what their transformation journey looks like. We simply activate the parts of their solution they need or the parts of our solution that they need for their solution as they need them.

So when we say low risk incremental modernization we mean you can firstly re-platform, then you can refactor and then you can kind of reimagine at your own pace and aligned with your business reality. Your end state isn't held hostage by a single approach. It's empowered by a solution that bridges the gap between migrating and truly modernizing.

00:09:21 Pedro

That's a very interesting approach. So you can allow companies to choose the pace that they are going. Now the next decision for leaders looking to migrate PL/I workloads is the target platform.

So you talk about no lock-in. Now they may think but if I go to some place that's all lock-in, a new platform. So what's the target platform?

How does Heirloom address this topic for clients?

00:09:52 Graham

Well we've talked about customer control and offering flexibility and that absolutely extends to our position on target platforms. Simply put we are 100% target platform agnostic. Heirloom customers can choose the platform that works best for them, any cloud, on-prem, even on mainframe modernization is supported.

Customers can choose one of these target platforms or a hybrid blend that fits their current needs and it's all totally flexible. So if the business changes direction or platform provider we can change to meet their new requirements. It's a true zero platform lock-in approach.

This is becoming more important with the rise of sovereign clouds. A Heirloom migrated application does not lock you into a single cloud platform. We have a client today that they migrate their first applications to the cloud but after living with the costs for a while they've decided to host their next applications in their own data center and move that existing cloud-based one back under their complete control.

This is trivial for them as applications migrated with Heirloom only have one hard prerequisite and that is a Java virtual machine.

00:11:22 Pedro

Okay and but we mentioned the skill short is around PL/1 and then you explain how complex solutions are written inside PL/I. How does Heirloom approach manage the cultural change that comes with a move from the language to Java for instance or other languages?

00:11:45 Graham

I mean great question. It comes back to this flexibility approach. We understand that customers have invested heavily in PL/1 and COBOL experts the SMEs and while they want to move to Java for access to a broader talent pool they know that the big bang language switch can and will be a risky move.

Our approach is fundamentally different in that we don't lock the PL/I application down and take it away for months on end and then bring it back as a completely different Java application. With the original PL/1 or the functionally equivalent Java code that our platform generates we are fundamentally a compiler so you can continue with the same skills as before to edit and compile at the PL/I level and from a people investment perspective this enables a controlled transition from PL/1 to Java if that's the desired end state. This means valuable PL/I resources the application SMEs who truly understand the application remain part of the process and they can continue to provide their knowledge while Java developers and resources get up to speed on that same application.

So staffing issues are managed and you can manage the knowledge transfer and skill transfer that takes place over time with no language big bang - it's a scaled transition and that's why we're talking you know while we're confident talking about our low risk customer control journey. With Heirloom there's no cliff edge no forced timeline it's truly incremental modernization path.

00:13:39 Pedro

Thank you for that that makes a lot of sense and it's very interesting we know there are many migration success stories out there including many Heirloom projects but it would be good to hear about Heirloom PL/I migration success or case study.

00:14:00 Graham

Great - I'm happy to talk about that we developed our PL/1 product primarily driven by a single specific client who had already tried and sadly failed to move a critical PL/I workload with another vendor. We were brought in by a leading SI and we worked closely with them to help this global automotive client do the migration of their core manufacturing and order management application. This mainframe PL/1 workload tracks a vehicle from the point of a customer order in in the sales room through lots of factory lines and manufacturing processes through to final delivery.

As you can imagine it's pretty complex mission critical workload and downtime just isn't an option. In fact we've been told that downtime that stops a plant would cost millions of dollars per day so I'm pleased to say the migration is a success and the core application was migrated and has now been running in production for nearly two years and there's been no event in those two years that has stopped the application so thankfully we've not had to suffer the consequences of millions of dollars of downtime.

This client's interesting though because and this highlights the flexibility that we have with Heirloom. The application was originally deployed to AWS Fargate with Tomcat as the application server but the application wanted to switch to AWS EKS and run using the Payara Java application server. We made this change almost overnight.

The client's architecture evolved but there was no change in the in the migrated application it just continued to work and it was trivial for us to alter the deployment architecture to match the client's preferred technology stack. This global automotive client's primary reason for selecting Heirloom was speed of migration and a pathway to modernizing its PL/I and COBOL application code base to Java and we continue to work with this client and they're developing new requirements on us all the time. Just now we're working with the same client to move data from DB2 on the mainframe to Postgres and this is for us at the application code level as simple as setting a compiler flag for automatic embedded SQL migration.

00:16:52 Becky

Thank you so much Graham and Pedro, a really great discussion today. The key message is clear, whilst COBOL modernization does tend to get most of the attention, PL/1 does represent a critical blind spot that really could derail your mainframe transformation strategy and as Pedro mentioned earlier with only five percent of legacy programmers actually able to handle PL/I and less than a third of modernization tools supporting it, it's really a challenge that organizations can't afford to ignore any longer. So the good news is that proven solutions do actually exist and we've heard today Heirloom's unique transpiler technology delivers the same proven approach for PL/1 as it does for COBOL and that gives you the speed control and the platform flexibility you really need to modernize your entire mainframe estate and in particular without that vendor lock-in or the risks associated with a big bang approach.

So here's my call to action, don't let PL/I become your modernization blind spot. If you have PL/1 workloads sitting alongside COBOL applications, reach out to Heirloom today to discuss how we can actually help you navigate a complete modernization journey that addresses all your legacy languages. Now you can find more information at heirloomcomputing.com or you can of course connect with us on LinkedIn and don't forget to subscribe to the Modcast series for more insights on mainframe modernization. So that just leaves me today to say one big final thank you to you Pedro for joining us again and thank you to you our subscribers for listening and we look forward to seeing you next time on the Heirloom Modcast.