Last updated on: Nov. 29, 2023, 4:54 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.
In the Discovery Phase, customers are introduced to the FixturFab team and design processes. We conduct a 1-1 discovery meeting to discuss your Test Fixture requirements at a high level (An NDA can be put in place if desired) and explain the difference between our development and production product lines and their respective applications. FixturFab will provide specific guidance on which of our products and services would be a good fit for your particular project.
After the discussion, FixturFab will provide budgetary pricing information and a proposed timetable for the Test System. For complex designs, the price range offered in the quotation may be fairly large to accommodate unresolved options or unanswered questions that remain about system implementation. In these cases, FixturFab may recommend a Blueprint Phase for the proposed system, where we can do some preliminary engineering work to address the loose ends and provide you with a more detailed quotation.
Preparing for the Discussion
Gathering a few details about your particular testing requirements is very helpful to get the process going in the right direction. In general, the discussion will cover the following topics:
- Device-Under-Test (DUT) dimensions?
- High-level test requirements — power supplies, specialized instrumentation, RF, etc.?
- Are devices being programmed? If so, what programmer is used?
- Rough number of test points involved & where they are located — top, bottom, or both sides of the DUT?
- Nature of the test points — pitch, involving connectors, location data available?
- Other devices that may participate in the testing — motors, switches, antennas, etc.?
- What PCBA design files will be submitted?
- CAD toolchain used, and design file formats?
- Review your preliminary test plan and requirements.
- Does the device have any regulatory, certification, or calibration requirements?
- Timeframe for delivery of the system?
Once you can answer most of these questions, the fastest way to get started is to submit a Request For Quote (RFQ).
Does Your Project Require Test Software?
Test Software can be a complex endeavor for any engineering team. FixturFab has developed a Python-based Test Runner that runs on a Linux platform and simplifies test software development. Deploying this framework, the customer writes only the custom Python Test Plan for their specific device, and the runner handles the rest:
- Test Fixture GUI
- PASS/FAIL notifications
- Account administration
- Test log organization, access, filtering, and downloads
- Multi-DUT fixture topologies
- Serial number scanning
- Deployment updates
FixturFab also provides turnkey software solutions leveraging the FixturFab Test Runner framework.
For FixturFab customers, Blueprint Phase activities and deliverables ensure thorough attention to fixture design details, reduce cost estimate ranges, and offer flexibility if, ultimately, the customer chooses another manufacturer. For FixturFab itself, Blueprints guarantee the systematic acquisition of requirements and serve as a proven roadmap for successfully completing complex Test Systems.
The Blueprint Phase duration varies with project complexity but typically lasts 1-4 weeks. If the complexity of a Test System warrants a Blueprint effort, a quote will be provided after the Discovery Phase.
Blueprint Value to Customers
The detailed Blueprint documents encompass comprehensive implementation details, ensuring meticulous attention to every facet of the system design, including hardware, software, test process, workflow, and a system qualification plan. The Blueprint design, as a service provided by FixturFab, prioritizes thoroughness, avoiding shortcuts that could result in costly oversights in terms of both expenses and timelines compared to alternative quotation methods.
After the Blueprint Report is delivered for review, the customer can ask additional questions, revise the project requirements, and ultimately approve the project. Importantly, if a customer chooses not to proceed with the final system build through FixturFab, the Blueprint Report remains a valuable resource that any other fixture manufacturer can utilize to support implementation elsewhere. Furthermore, the Blueprint significantly narrows the range of the cost estimate (quote) provided to the customer by FixturFab, offering clarity and transparency in the project's financial aspects and delivery timeline.
- System Block Diagram & Cabling Plan
- Test Instrumentation Selection
- Test Matrix (Test Plan mapping to test hardware and/or API resources)
- Qualification & Acceptance Plan
- Bill of Materials
- Milestone Schedule
- Refined Quotation for Project Cost
Blueprint Value to FixturFab
The Blueprint Phase is integral to the efficiency and success of the design process. The resulting documents serve as a structured means of acquiring all requirements and design resources, ensuring a systematic approach to each project. The Blueprint process provides a proven roadmap for navigating the complexities of designing intricate test systems where multiple design considerations overlap. This thorough and well-documented approach not only facilitates the smooth acquisition of necessary design elements but also acts as a reliable guide for the team, contributing to the successful completion of complex test systems within the specified parameters.
Customer Requirements for a Blueprint Quote:
- PCBA manufacturing files: Gerbers, ODB++, or IPC-D-356 files.
- 3D PCBA Model (STEP)
- Test Point list
- Detailed Test Plan
- Instrumentation preferences (optional)
- Physical DUT (optional)
Submitting a Request For Quote is the fastest way to get started.
Test Matrix Example
The Test Matrix maps available nets from the test points to the test instrumentation channels and each test case in the PCBA Functional Test Suite. Completing this is vital to avoid missing anything critical in the final, manufactured system.
Architecture & Cabling Plan Example
Key architectural example features
- Test System tests 6 DUT devices concurrently.
- Test results for each DUT are communicated to the operator via RGB panel indicators co-located by each individual DUT.
- Modular design has self-contained test slots, each with independent instrumentation, communication, and power supply resources
- System is fully automatic (button pushing and LED detection is automated), requiring no physical participation from the operator other than loading and unloading the DUTs.
- Fixture communication is achieved over a dedicated, high-speed USB network
- Fixture detects open/closed status, ensuring safe operation, and automatically counts insertion cycles for maintenance tracking purposes.
- The CPU subsystem runs FixturFab’s Test Runner framework (Python-based) on a Linux-based OS, coordinating test operations, logging results, and providing a GUI interface to the operator.
In the next part of the Test System Development Process series, we dive into details of the mechanical and electrical engineering completed during the Design Phase.