Last updated on: Nov. 20, 2023, 12:28 p.m.
Test System Development Process
Test Systems are designed to execute automated Functional Test Plans, and are most often implemented in production-level fixtures (development-level fixtures also occasionally fall into this category). Simple Test Fixture Designs (mechanical-only fixtures) do not require this level of design effort. FixturFab has developed a standard, comprehensive process for designing Test Systems that will be explored in this series of articles.
Python stands out as an excellent software platform for modern Test System automation. Its non-proprietary nature ensures widespread compatibility, and Python wrappers are well-supported for various test instrumentation. Additionally, it boasts modest CPU hardware requirements, making it efficient for diverse systems. The language's extensive library support extends to modern cloud-based architectures, facilitating seamless software deployment, monitoring, and retrieval of test information.
FixturFab Test Runner
Test Runner is a Python-based test framework created by FixturFab for Test System automation. It is deployed on an underlying Linux OS platform, using easy-to-manage container distribution methodologies. Following the pyTest paradigm, it streamlines test automation by necessitating only the creation of a Test Plan as custom code for any particular Device Under Test (DUT).
Test Runner offers a user-friendly GUI front-end with test control & status features (i.e. start, cancel, pass, fail, etc.), serial number scanning, log file viewing & filtering, and output file generation. Additionally, it includes user account management distinguishing between admin and operator roles. The framework incorporates robust database management for storing and retrieving log files, while also controlling pass/fail test limits.
FixturFab customers may elect to engineer their own software solution to automate their new Test System, or use Test Runner as a starting point to implement just the Test Plan for their DUT. FixturFab can also develop fully turnkey software solutions for customers that lack the software resources and/or time to tackle the Automation Phase.
During the Blueprint Phase, FixturFab prepares a comprehensive Qualification & Acceptance Plan, outlining the final testing of the integrated Test System. The test encompasses software, hardware, and mechanical components to provide evidence of compliance with testing requirements and determination that the completed system is ready for delivery.
While every plan is tailored to address the specific requirements of each Test System, the following areas of qualification testing are commonly included:
- Tester Measurement Compliance - Do test measurements comply with PASS / FAIL criteria outlined in the Test Plan?
- Tester Calibration Effectiveness - Do calibration mechanisms used to improve tester accuracy and/or variance work as designed?
- Tester Mechanical Repeatability - Can the test system repeat measurements after physical DUT removal and insertion without compromising the test outcome?
- Tester System Stability - Can the test system run continuously for a timeframe representing a typical manufacturing shift (>= 8 hours) without rebooting the system or needing other system intervention?
- Test Slot Interoperability - What variance can be expected from slot-to-slot in a multi-slot fixture configuration?
- Test System Interoperability - What variance can be expected between two or more identical fixtures?
Once a Test System has passed the Qualification & Acceptance Plan, an associated test report is submitted by FixturFab for the Customer’s review and approval. All log files and/or data that has been collected as part of the testing efforts are organized and made available with this test report.