When an engineer releases a build-to-print test system, it can feel like crossing the finish line of a marathon.
The design is complete, the drawings are issued, and production can begin. Everyone is happy, right?
Right?
Not exactly. The reality is that the moment the system is released, THAT is the actual starting line for manufacturing execution. If critical details are missing or ambiguous, the build phase can quickly become a cycle of scope changes, delays, and costly redesigns.
At Ball Systems, over the last six decades, we’ve learned a thing or two. Chief among those lessons is that the most successful build-to-print test system manufacturing efforts share one common trait: engineers lock down the technical specifications and communication pathways before the project begins.
Below are five areas engineers should define before releasing a build-to-print test system into production.
1. Lock Down the Core Technical Specs
This sounds like it should be a no-brainer, and, in fairness, it often starts out that way. Before a build-to-print project begins, engineers should ensure the technical requirements are fully defined and documented. This includes complete electrical schematics, detailed mechanical drawings and layouts, and a finalized bill of materials (BOM). The system architecture should clearly define how subsystems interface with one another, along with environmental requirements and expected performance specifications.
Without these details, a manufacturing partner is forced to interpret design intent rather than execute a precise specification. Assumptions in this business are never a good idea. Simply put, we’re not psychics.
In build-to-print manufacturing, the goal is simple: build exactly what the customer specifies. When specifications are incomplete or keep evolving, the project quickly shifts into a hybrid design-build scenario that introduces uncertainty, slows production, increases project risk, and a lot of finger-pointing from all sides.
At Ball Systems, project engineers emphasize that the most efficient builds arrive with fully documented designs and clearly defined components. When that level of preparation exists, production teams can focus on quality execution instead of reverse-engineering design intent or resolving missing information.
In baking, you know cookies are done when they’ve been baked at the correct temperature for the right amount of time. In automated test system projects, however, defining “done” is rarely that simple.
What does “done” actually look like?
Acceptance criteria should be defined early and incorporated directly into the project’s statement of work. Engineers should establish measurable pass/fail thresholds for test measurements, define required performance benchmarks for the system, and outline the validation procedures that will confirm the system operates correctly. Environmental conditions for acceptance testing should also be specified, along with any documentation required for delivery.
When acceptance criteria are clearly defined and agreed upon from the beginning, both engineering teams and manufacturing partners understand what successful completion looks like. Without that clarity, projects risk devolving into debates over whether the system meets expectations, even when it technically meets specifications.
The consequences of unclear acceptance criteria can become very real during execution.
A while back, Ball Systems worked with a US automaker to create what ultimately ended up being two separate systems. The first was a lifetime tester used to evaluate engine controllers for pickup trucks, simulating roughly ten years of driving conditions on the ECU electronics to verify that the controllers could meet the durability and warranty expectations promised by the manufacturer. The second system was an EMC tester, originally designed by a previous engineer. As the name suggests, it evaluated electromagnetic compatibility by injecting various types of electrical noise and potentially harmful signals into the engine controller.
Throughout the course of the project, the acceptance criteria kept changing at the hands of those multiple chefs in the kitchen I mentioned earlier. We could have the tester run for a week, and it would say the engine controller passed, because at the end of the day, all that came up on the screen was pass or fail. It needs to pass 10 units.
The customer got very particular and said, ‘Well, send us all the data from that one week run, and then say, this signal might have passed, but do you see here on our 73, there was this little one millivolt glitch. That's not a good signal’.
At that point, we stepped back internally and said wait a second - it's within the bounds. It says pass. Our team didn't say we were going to go through 10 days’ worth of data minute by minute.
Long story short, what “done” looks like absolutely must be defined at the outset of a project.
Along those same lines, while hardware often receives the majority of attention during test system design, software architecture frequently determines long-term success.
Engineers should define the test sequencing framework, data logging and storage formats, and hardware abstraction layers that allow the system to interact with instruments and devices under test.
Many modern automated test systems rely on modular instrumentation platforms such as NI PXI hardware combined with LabVIEW and TestStand to manage complex measurement workflows. Modular architecture allows engineers to scale systems as product requirements evolve.
For example, Ball Systems engineers have developed PXI-based automated characterization systems capable of executing thousands of test permutations across voltage levels, temperature conditions, and device configurations for mixed-signal ASIC development.
By defining the software architecture before the build begins, engineers ensure that the final test system remains flexible, scalable, and easier to maintain over time.
A production test system’s lifecycle rarely ends when the system ships. In many industries, test equipment remains operational for decades.
Engineers should consider long-term operational factors during the design phase, including component obsolescence, calibration schedules, field upgrades, replacement part availability, and future software updates. Test systems supporting industries such as aerospace, automotive, and defense may remain in service for 10 to 20 years or longer.
Without lifecycle planning, maintaining those systems can become expensive and unpredictable as components reach end-of-life or software environments change. A well-defined lifecycle management strategy ensures the system remains serviceable and maintainable long after the original development team has moved on.
Comprehensive documentation is the backbone of any successful build-to-print test system project.
Engineers should define exactly what documentation must accompany the delivered system. This typically includes as-built documentation that reflects the final hardware configuration, complete wiring diagrams and schematics, software source code and revision histories, and calibration procedures. In addition, engineers should specify the required test data, validation reports, and data storage formats needed for traceability.
Clear documentation protects intellectual property while ensuring future engineering teams can operate, troubleshoot, and maintain the system. It also provides the traceability required in regulated industries such as aerospace, defense, and automotive manufacturing.
Even with excellent documentation, communication between engineers and manufacturing partners is the real driver of project success.
At Ball Systems, technicians, project engineers, and production teams collaborate closely with customers throughout the build process to clarify specifications, identify potential gaps in documentation, and confirm that designs are executable before production begins.
That ongoing communication prevents small misunderstandings from turning into major production problems.
When engineers and build partners maintain transparency from day one, projects move faster, risks are reduced, and the final test system performs exactly as intended.
Releasing a build-to-print test system is not simply a matter of handing off drawings. It requires providing enough clarity that a manufacturing partner can execute the design without interpretation or guesswork.
In production testing environments, reliability is not optional – it’s mission-critical.
At Ball Systems, we've spent more than six decades manufacturing complex test systems for aerospace, automotive, and defense customers who can't afford surprises on the production floor. When your design arrives with locked specs, defined acceptance criteria, and clear documentation, our team hits the ground running with no guesswork, no delays, just precise execution.