Which mistake is the most expensive?

An incomplete or inconsistent BOM. A missing part or an outdated revision stops the order after materials are bought, and the cost is the schedule, not the component. Send the BOM with manufacturer part numbers and a revision.

Why state the test plan on the order?

Because test access and fixtures are decided at layout and quotation. A test requirement added after tooling may need new pads, a fixture or a different assembly flow, all of which cost more than deciding upfront.

Blog

Six Common Assembly Order Mistakes

Most delays on an assembly order are created before the order is sent.

Hitech Circuits Engineering Desk

Shenzhen, China · PCB fabrication and assembly

2 min read

Published: 2018-08-07

Last updated: 2026-10-18

Technical review: Process figures checked against our published capability sheet. View capability sheet

1. Incomplete BOM

Missing manufacturer part numbers, alternates or revision control.

2. Unclear assembly drawing

Which side is populated, polarity, and parts fitted or not fitted.

3. Finish chosen late

A finish that does not suit the pitch or the storage time forces a re-quote.

4. No test plan

ICT, flying probe or functional test need access and fixtures decided early.

5. Unstated customer-supplied parts

Free-issue parts need incoming inspection and kitting time.

6. Logistics left to the end

Incoterms and documentation decide the actual delivery date. All six are answered by one complete data package — which is also the first thing a pcb assembly services review checks.

Technical Specifications

Engineering review: free DFM/DFA before tooling
Quality gates: IQC · IPQC · QC · QA
Acceptance: IPC-A-610 workmanship

Frequently Asked Questions

Which mistake is the most expensive?
An incomplete or inconsistent BOM. A missing part or an outdated revision stops the order after materials are bought, and the cost is the schedule, not the component. Send the BOM with manufacturer part numbers and a revision.
Why state the test plan on the order?
Because test access and fixtures are decided at layout and quotation. A test requirement added after tooling may need new pads, a fixture or a different assembly flow, all of which cost more than deciding upfront.

← Blog

Related engineering notes

Request a customer quote

Free engineering review and quote for PCB manufacturing, PCB assembly, component sourcing and box build.

Request a Quote Explore Capabilities