What is “Line Clear” and Why Should Your Robot Care?

Wanted to explain something important that most people don’t understand or fully consider when implementing advanced robotic machine tending for production in regulated industries; the topic is Line Clearance and how it relates to Production Changeovers when using robots.

Let’s start with FDA regulated industries – Medical Devices, Pharmaceuticals, and Biotech – although Line Clearance is relevant in many other sectors like Defense, Space and Aerospace, as well as, Semiconductors, Automotive, and others. It’s just referred to by different terms like Changeover Verification, FOD Sweep, or Lot Clearance.

As specified in ISO 13485 / FDA CFR 21 Part 820, “Line Clearance” is the formal process of verifying that a production line is clear, clean, and free from previous product or material. In other words, that it is ready for the next product, part lot, or batch.

It’s critically important in pharma, bio, and med dev manufacturing, and part of the standard Current Good Manufacturing Practices or CGMP to:

• Prevent mix-ups between different products or batches
• Ensure traceability isn’t compromised
• Maintain compliance with Device History Record (DHR) and labeling control
• Reduce risk of cross-contamination

Line Clearance is also essential for Traceability Implementation Practices:

• Use of barcodes or UDI labeling (Unique Device Identification)
• Keeping Device History Records and DHR links to DMR (Device Master Record)
• Ensuring electronic records are secure and audit-capable (if using systems like eDHR)
• Lot and batch tracking in ERP/MES/QMS systems

Here’s how Line Clearance and Automated Changeovers should be managed.

First, you must make sure robotic production is Traceable and that the Line Clearance requirements are met with certainty before performing a Changeover.

This is why our robotic production software is structured around parts and their associated orders or lots. Each part staged for automation is assigned a unique identifier based your UDI system – such as a serial number or a sequential extension of the lot number – along with all required manufacturing data, including machine programs, automated inspection programs, tolerances, and any other configurable attributes relevant to that specific part.

When a robot picks up a part from the infeed, Flexxbotics robotic production software designates exactly which part is being handled and tracks that part through the entire process.

As the part progresses through each machine in the robotic cell, our software tracks its location, movement, and maintains a digital record of where it’s been and what operations have occurred. By the time the part reaches inspection, Flexxbotics has an unbroken chain of traceability – also known as a complete Digital Thread – that links the inspections conducted and their results directly to the unique part identifier.

This identifier is essential to maintaining a compliant Device History Record (DHR). In manual processes, operators typically enter serial numbers or unique identifiers by hand during inspection. However, in an automated cell, robotic production software must be able to track this information through each parts movement and then automatically propagate each part’s identifier onto the inspection report, ensuring the traceability requirement of ISO 13485 is fully met – without relying on manual input.

Line Clearance and Changeover

Line clearance is inherently supported by Flexxbotics. Because part-level tracking is handled in our software, physical segregation of parts on the infeed occurs without modifying robot code. The robot follows a consistent motion routine; when our software detects a part’s position, it processes it according to the production routine.

Our robotic production software enables fast, validated changeovers without requiring human intervention to delete outdated programs or manually load new ones. Flexxbotics ensures the correct process data is loaded for each specific part. This process can be validated and is superior to relying on manual changeovers which can be prone to data entry mistakes.

Why PLC-based Systems Fall Short

Today, most companies rely on PLC-based systems, which lack the data architecture required for unified, part-based traceability. PLCs are fundamentally register-based, making it difficult and error-prone to track a wide array of parameters – especially when dealing with 10, 20 or more unique attributes per part. PLCs do not offer built-in support for high-level data structures, dynamic database schemas, or modern APIs.

To replicate Flexxbotics level of part traceability, someone would need to custom-develop a full software stack on top of the PLC: including the data model, logic engine, part tracking architecture, program loading routines, run-time parameter/variable setting capabilities, HMI, alarms, reporting infrastructure, and more.

This is complex enough for a single robotic cell, and does not scale consistently across dozens or hundreds of robots in a factory.

Therefore, implementing Line Clearance and Traceability on a cell-by-cell, project-by-project basis is impractical and cost-prohibitive. Not to mention highly prone to implementation variation and validation challenges.

In contrast, our Flexxbotics robotic production platform delivers all of this and more out of the box, with a software-defined control architecture that scales across robotic cells and product types, while maintaining full compliance with traceability and line clearance requirements for automated changeovers.

For more insights into advanced robotic machine tending, you can get our Complete Guide to Robot Machine Tending white paper, or if you’d like to discuss an upcoming project, get in touch with us directly.