Windows Instrument Control Software – 21CFR Part 11 Compliant

Project Description

The Problem
An European Analytical instrument manufacturer supplying equipments to Pharmaceutical companies needed to develop a Windows application. The application had to support easy editing of methods that run on the instruments. The running of the tests should be controlled by this Windows application, the results should be collated, analyzed and reports needed to be generated. All the features had to be compliant to 21 CFR Part 11 ensuring that only authorized personnel have access to the right set of features and every significant event is audited and traceable to the date, time and the user.

The user interface had to project a modern instrument software look and feel. It should be easy to use as well as should have a presentation that is at the cutting edge of contemporary graphical user interfaces. It should also fit in to a test laboratory environment.

The Solution
Microsoft’s Windows .NET was the right platform for this application. The entire system was architected to ensure that the security features like authorization and auditing was built-in and that it was inherent to the software. This ensured that these features cannot be by passed by any means.

An instrument Graphical User Interface (GUI) specialist designed the screens using Expression Blend tool which was hooked up to the back end code in C#. At a very early stage the contract between the GUI designer and the programmer was established. This allowed complete decoupling of the presentation aspects of the application from the implementation aspects of the features. The GUI was prototyped and reviewed by the client’s sales and marketing team. It was beta tested at few of the client’s customer locations to get feedback. The customer usability testing yielded useful information that was rolled in to the modified GUI screens.

The MS-SQL was chosen as the database. Encryption was used to ensure that the database records cannot be tampered with. Linq technology was used for accessing the database. This allowed the software to be completely object oriented. User management, Method editing, version tracking, test results analysis, charting, reporting, audit trails were all implemented in a modular fashion, allowing easy enhancement and maintenance of any of these features. Every significant event would be time stamped and stored in the audit trail.

The instrument connects to the software over a serial port. The commands were encapsulated in a communications class. This helped in easy migration of the communication module later when the instrument was enhanced to support a LAN interface.

NUnit was used to test each of the modules individually. The target of 100% coverage during unit testing was achieved for all critical modules. The system testing too was automated. This enabled the regression test suites to be executed easily even for all interim releases. Automated tests helped release the software to the market which according to the client was one of the most robust software releases.

The newly designed Graphical User Interface (GUI) was welcomed by the client’s market and coupled with the robustness of the software and the 21 CRF part 11 compliance, the client was able to increase the sales revenues by 22% in the very first year of release.

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