Case Study: Reducing Software Validation Time and Code Change Risks

When new code is added to an existing system, the software must be re-validated. This takes time so can be a costly exercise. In addition, code changes in themselves introduce risk, something which can be compounded with human error and accuracy issues.

As a result, it is a complex process to validate software when code has been changed. Plus, tracking the history of code changes is challenging as code can be difficult to manually compare, making regulatory compliance and supporting audits by regulatory bodies a time-consuming process.

One of our customers at SL Controls wanted to address these issues to make software development processes more efficient. Specifically, they wanted to simplify the complex and time-consuming processes of validating software.


  • Reduce software validation time by highlighting changes in different versions of code
  • Reduce risks from code changes
  • Assist in future software development, implementation, and testing activities
  • Reduce the need for testing of future code when rolling out code to new lines that had been previously validated

What We Did

At SL Controls, we had previously developed software to compare versions of code. We used this as the basis for the new tool, leveraging the previous development work while implementing improvements identified by the customer. This enabled faster completion of the project so the customer could quickly begin utilising the new software tool.

Detailed scoping meetings began in early 2019 between the customer and the SL Controls’ technical team of System Architects and Software Developers. We took a strong team-wide project management approach from the start. This involved creating a detailed breakdown of the schedule and work completed to give the customer maximum visibility and oversight of the project’s progress.

The above was developed to fit with our agile software development approach at SL Controls to ensure consistent progress.

The software solution we developed was compliant with the customer’s coding standards.

In addition, extensive functional testing and stress testing was mapped out and completed, a process that was reviewed regularly with the customer.

The above testing was also peer-reviewed by System Architects at SL Controls.


SL Controls created an effective custom software tool to efficiently compare versions of PLC code. The software includes reporting features and review and history functionality. The customer is now using this to simplify future code validation, track the history of changes in code, and support audits by regulatory bodies.

The time it takes to produce reports is greatly reduced while accuracy has been increased by eliminating human error.

In addition, the software generates history reports and code review reports automatically. All reports are standardised to make code version comparisons more efficient.

The project was completed on-time and delivered on the expectations and requirements of the customer.