Why Rules-Based IDP Can’t Keep Up with Modern Documents

For a long time, rules-based IDP was the sensible choice.

If a document followed a predictable structure, rules worked. You defined where fields lived, how they looked, and what to do with them. The system did exactly what it was told — no more, no less.

The problem is, modern documents don’t behave that way anymore.

Rules work…until they don’t

Rules-based systems assume consistency. Same layouts. Same wording. Same structure, every time.

That assumption breaks quickly in the real world.

Invoices change formats. Contracts evolve. PDFs arrive scanned, rotated, or stitched together. Tables move. Fields disappear. New document types show up without warning.

Each change requires another rule, another exception, another round of maintenance. Over time, systems become fragile — and teams spend more time fixing pipelines than using the output.

The cost of rigidity

Rules don’t understand context. They don’t recognize intent. And they don’t adapt when something unexpected happens.

That leads to:

• missed or misclassified data
  
• constant manual review
  
• growing technical debt
  
• slower onboarding of new document types

The more rules you add, the harder the system is to maintain – and the less reliable it becomes.

Modern documents need modern intelligence

Today’s documents are unstructured, inconsistent, and full of edge cases. They require systems that can reason, not just match patterns.

GenAI-powered IDP approaches documents differently. Instead of asking “Does this match a rule?”, they ask “What does this information mean in context?”

That shift allows systems to handle variation naturally, adapt to new formats, and make sense of documents even when structure breaks.

From brittle logic to resilient understanding

When understanding replaces rules, IDP becomes far more resilient.

New layouts don’t require reconfiguration. Slight wording changes don’t break pipelines. Documents can be processed based on meaning rather than exact placement.

The result isn’t just better extraction – it’s more trustworthy output and fewer surprises downstream.

The takeaway

Rules-based IDP solved yesterday’s problems. Modern documents present a different challenge.

As document complexity grows, intelligence matters more than precision. Systems that rely solely on rules struggle to keep up, while systems that understand context continue to improve.

The future of IDP isn’t about writing better rules.
It’s about moving beyond them.