Write the questions before ordering the board
Identify the decisions the prototype must support: basic function, interface timing, power behavior, thermal performance, mechanical fit or manufacturing feasibility. Assign measurable acceptance criteria where possible. A prototype that simply powers on may leave the most important product risks unresolved.
Select a construction and assembly configuration representative enough for those questions. A breadboard or simplified circuit can support early learning, but it may not reproduce the geometry, materials or environment of the intended product. Record those limitations.
Prepare an observable and controlled build
Include useful test access, programming connections and a safe, appropriate measurement approach in the design review. Define the BOM, fitted variants, firmware and any planned temporary modifications. Ensure the files supplied for fabrication and assembly describe the same revision.
Before testing, inspect the received assembly and record its identity and known deviations. Check that the test setup uses the intended interfaces and operating conditions. A result is difficult to interpret if the hardware, software or measurement configuration is uncertain.
Separate validation from production screening
Design validation asks whether the product meets its requirements. Production tests screen manufactured units against a defined acceptance procedure. Some equipment and measurements can serve both, but the objectives and coverage are not identical.
Capture failures, conditions and corrective actions in a reviewable record. Distinguish a design correction from a temporary bench workaround. Repeat affected tests after changes and consider whether the correction alters another interface or operating mode.
Close the handoff to the next build
Issue a controlled revision with resolved findings, updated files and an explicit list of remaining questions. Define the first-article gate and production test requirements before increasing volume. Do not transfer undocumented prototype modifications into a repeat order.
Confirm sourcing, fixtures, assembly instructions and acceptance evidence for the proposed production configuration. Keep lessons from the prototype linked to the relevant design decisions. The value of the prototype is the uncertainty it resolves, not only the physical samples it produces.