It’s a familiar story. A system interface keeps showing up on the agenda — again. It’s mentioned in every business review, flagged in every update, and has quietly become part of the landscape. It’s been “fixed” more times than anyone can count, yet somehow, it never quite goes away.

And while the instinct is to hand it straight to IT, the root cause often lies elsewhere. In many cases, these interface problems are actually business issues in disguise — caused by misaligned processes, inconsistent data, or operational changes that never fully made it into the systems landscape. The interface is just where it all comes to light.

And so, predictably, IT gets the call. They patch it. It works — until the next cycle when the same issue returns. Again.

The question isn’t why IT can’t fix it. The real question is: what exactly are we fixing?

Not Every Interface Problem Is a Technical One

Not all interface issues are rooted in code. In many cases, they’re symptoms of business misalignment — mismatched processes, inconsistent data management, or upstream changes that never made it to downstream systems.

Because the problem manifests technically — as an error, a failed job, or missing data — it’s logical to ask IT to step in. But if the source of the failure is a process gap or misaligned data, IT will only ever be treating the symptom, not the cause.

Most IT teams or SAP consultants don’t have visibility into the business side of operations. Their job is to ensure the interface runs correctly. If the data coming in doesn’t meet expectations, they can reprocess or patch it — but they can’t rework the business logic behind it.

Over time, some businesses stop raising these issues altogether. A workaround becomes the norm. One client had a daily ritual: “Correct the SAP iDoc, reprocess, and move on.” It worked — up to a point. This daily correction routine never tackled the root cause of the iDoc error. In fact, the information entered into the iDoc to make it pass wasn’t always a true reflection of what actually happened operationally. It simply pushed the data through — bypassing the real issue while creating discrepancies elsewhere in the process.

When the business evolves — a new 3PL partner, an added warehouse, or a merger — those inconsistencies compound, and the cracks widen fast.

It’s not that the interface is unstable. It’s that the business has changed, and the underlying processes haven’t kept pace.

Three Business Misalignments That Trigger Recurring Interface Failures

1. Misaligned Master Data

When two systems communicate, they rely on consistent data. If your master data is misaligned, even slightly, interface issues are almost guaranteed.

A common short-term fix is a one-off data cleansing exercise. That may stop the immediate errors, but if the master data management processes aren’t improved, inconsistencies creep back in.

Take this example:

Your SAP system tracks product quantities in litres, but your logistics partner uses gross weight. That’s manageable — as long as both sides maintain the correct master data. An interface can easily convert between units — provided the underlying data is accurate and aligned.

Now imagine a beverage supplier running a promotion: bottles of drinks with “10% extra content for free” for a limited time. To keep things simple for customers, the SKU number is not changed — so customer orders and pricing remain unaffected. However, the physical characteristics of the product have changed: the volume in litres has increased, which means the gross weight is no longer the same.

If you don’t immediately update the master data on both sides — including the new weight — the interface will fail. The system trying to reconcile litres against weight will find a mismatch, and errors will start to surface. And they will keep surfacing.

And this isn’t just a matter of updating master data once. It needs to be built into a proper Product Lifecycle Management process. The business must know exactly when the promotional stock will be depleted and ensure that the master data is switched back at the right moment — not too early, not too late. If that step is missed, the interface will start failing all over again.

2. Disconnected Upstream and Downstream Processes

This is another classic: upstream processes that do not match downstream ones. Misalignment arises when operational practices or data definitions (like batch numbers, serial numbers, or production dates) aren’t consistently maintained. Without harmonising these definitions along the supply chain, interfaces inevitably produce errors.

As an example:

One company we worked for had a challenge with the production dates of batches. The manufacturing team saw a batch as only having one production date — for example, when they produced 5,000L of a liquid in one go. However, it took several days to fill that into bottles, and the filling line would print the actual date of filling on the bottle.

The challenge? On regular occasions, the 3PL warehouse had to manually enter picking information into their system. This led to the interface erroring out when it confirmed what batches and dates had been picked — because the date on the label (the filling date) didn’t match the production date recorded in SAP.

Similarly, return orders regularly incur delays upon receipt. When products came back, the 3PL operator would manually enter the date printed on the bottle into their WMS. However, since that date didn’t always match SAP’s production date record, the inbound interface would fail again. The data wasn’t incorrect — it was simply misaligned due to a process gap.

You cannot fix this at the interface level; you have to align the upstream and downstream process definitions and agree on consistent operational practices.

3. Incompatible Data Formats for Downstream Use

Interfaces must deliver data in a format that is recognisable and usable for downstream processes. Even when the content is technically correct, any inconsistency in format can trigger errors or delays — often in ways that aren’t immediately obvious.

Here’s an example:

One client’s SAP system generated a batch number such as 0000123. This value was passed through the interface to the warehouse management system (WMS), and under normal conditions, picking processes used scanners to identify the product. The system would then automatically confirm the correct batch number — 0000123 — as originally received from SAP.

However, in reality, manual interventions still happen. During picking, confirmation, or packing, operators sometimes have to enter the batch number manually — especially when scanning isn’t possible or when exceptions occur. And naturally, the operator enters what they see printed on the box: BIRM123.

The problem? That label was created by the factory, which had chosen to include the site code in the batch number on the packaging — something like BIRM123 instead of matching SAP’s 0000123. As a result, the return interface failed. The outbound interface may have passed cleanly, but the inbound one couldn’t reconcile what the WMS reported back.

Again, the interface wasn’t broken. It received a value it couldn’t recognise because it wasn’t formatted as expected. The root issue was a disconnect between what the business printed and what the system was told to expect.

To fix this, the data preparation and labelling process upstream must be aligned with downstream system logic. If manual entry is a reality on the floor, then what’s printed must match what’s stored — consistently. Otherwise, you’re building in silent failure points that only show up when it’s too late.

From Temporary Fixes to Lasting Solutions

Recurring interface issues aren’t a sign of poor systems — they’re signs of misaligned processes, inconsistent data, or undocumented changes. IT may be the first line of defence, but if the issue sits in the business process, it needs a business-led solution.

At ABA, we bring both sides to the table. Our consultants combine business process insight with deep SAP expertise, enabling us to identify root causes quickly and fix them — not just patch them.

As one SVP of Supply Chain at a global chemicals client put it:

“I don’t know many people who can flip the switch between Process Improvement and SAP. ABA consultants have deep knowledge from both a business and technical side, and how it works across all modules.”

Ready to Resolve Those Long-Standing Interface Issues?

Whether it’s a short engagement or a full root cause review, our team works fast and delivers with clarity. We offer hands-on, senior expertise to align your systems and processes — and finally put an end to the cycle of recurring interface errors.

For more information, contact us to book free review call and explore our 2-15 day SAP Work Packages