Building GAMP 5-Compliant Pharma Solutions: A Software Engineering Approach to PLC Programming

There’s a common belief in pharma automation that as long as the machine runs, the software is “fine.” But that mindset rarely survives a regulatory audit.

GAMP 5 compliance demands more: provable, risk-managed, and lifecycle-controlled systems. At the core of this lies the PLC layer – the code that drives core pharma manufacturing activities like fluid flow, dosing logic, CIP sequences, and safety interlocks.

Yet in many vendor ecosystems, PLC programming remains detached from formal software lifecycle practices. It often gets patched, duplicated, or versioned in silos and documented only after the fact.

The real challenge is this: GAMP 5 doesn’t just ask if the code works. It demands to know why the code was written, how it ties to risk, and what traceability exists from user requirements to implementation.

Vendors who understand this shift have started evolving their development approach. They build solutions that inspire lasting confidence – from the first User Requirements Specification (URS) review to the last rung of ladder logic.

Why Compliance Demands a Software-First Mindset

Compliance is often framed around devices, enclosures, and hardware certifications. But true compliance strength lies in how the software, especially PLC logic, is designed, tested, and managed.

Treating PLC programming as software engineering means embedding quality, risk logic, and traceability directly into the code. Not retrofitting it post-hoc. Not stitching documents afterward.

This mindset reframes PLC code from an infrastructure tool to a strategic compliance asset, one that holds up in audits, accelerates validation, and aligns cleanly with product goals.

Start with Software, Stay with Traceability

GAMP 5’s principle is clear, “quality must be engineered into the product lifecycle from the start.” From requirements and design to coding and release, every phase must support traceability and risk alignment.

For PLC programming, this means writing code that is directly traceable to functional specifications and risk assessments. Every rung of ladder logic, every function block, should have a clear purpose linked to compliance goals.

This embedded approach eliminates the costly, error-prone cycle of “papering” compliance after development. Instead, it creates a product that is inspection-ready at every stage.

PLC Programming as Software Engineering, Not Infrastructure

Too often, PLCs are treated as project utilities. Something the automation team wires together and hands off. But the teams making the biggest progress with digital pharma platforms see things differently.

They treat PLC logic like they would any high-impact software module: designed for clarity, tested with intention, and released through a structured pipeline.

That mindset transforms how teams build.

➜ It unlocks libraries of validated function blocks that can be reused across machines and lines.

➜ It encourages integrated toolchains that connect PLC editors with lifecycle systems like Jira or Polarion.

➜ It brings DevOps-style traceability to embedded environments with commit histories, automated test outputs, and change approvals.

What GAMP 5 Expects from Your PLC-Driven Pharma Solution?

GAMP 5’s risk-based framework guides vendors to focus validation efforts where they matter most.

For PLC code, this means:

➡️ Structured Development:

Code modularly, using reusable validated function blocks that represent discrete, testable functions.

➡️ Traceability:

Link each code module back to user requirements and risk assessments. Maintain trace matrices that cover PLC code and system-level design.

➡️ Version Control:

Use tools that enable structured version management of PLC programs alongside documentation and testing artifacts.

➡️ Change Management:

Ensure every change in PLC logic is reviewed, approved, and documented before deployment.

Following these practices transforms PLC programming from a hidden black box to a transparent, compliant software asset.

Software Challenges and Solutions in Achieving GAMP 5 Compliance

What Software Vendors Can Deliver That Automation Vendors Can’t?

Vendors focused on lifecycle-driven software deliver something beyond functional control. They deliver confidence.

That confidence matters at every level:

✔️ To the Engineering Team: It means faster builds, easier change control, and reusable assets.

✔️ To the Quality Lead: It means every system aligns with validation expectations.

✔️ To the Client Procurement Team: It means they’re investing in a solution, not a workaround.

✔️ To Auditors: It means the system is inspectable, explainable, and well-governed.

Here’s How Software-led Teams Stand Apart:

The Business Gains for Pharma Software Vendors

Across Europe and globally, pharma manufacturers are leaning heavily on automation partners who can stand tall in audits, scale across validation-heavy environments, and offer confidence with every release.

For software vendors, this shift offers significant competitive and commercial value.

Azilen’s Perspective: Compliance as a Software Outcome!

When vendors bring lifecycle thinking to the logic level, not just the UI or database, they create systems that inspire confidence. Confidence from quality leaders who sign off on audits. Confidence from validation teams who trust the traceability. Confidence from clients who rely on systems to scale without uncertainty.

At Azilen, we help pharma solution vendors build GAMP 5-compliant platforms where PLC programming, lifecycle alignment, and traceability move together.

If you’re building for regulated markets and view compliance as a business enabler, let’s explore how to scale that mindset into your engineering practice.