Illustrative data package: an EMS provider's BOM-to-yield records

What does an EMS BOM-to-yield data package contain?#

An EMS BOM-to-yield data package contains the linked records that follow each customer program from the request for quote to the yield on built lots: the scrubbed BOM, the quote revisions, the work orders, the inspection and test results and the yield outcome. The value sits in the links, because they show how decisions made at quote time played out on the line.

Everything on this page is illustrative. The company, programs and files are fictional, and the manifest is a template an EMS owner can hold up against their own ERP, quoting tool and MES before a fit check. Nothing here describes a real customer or a real transaction.

Read it as a map, not a requirement. Few EMS providers keep every link shown here, and a package can still be useful when some steps are thin, provided the gaps are written down rather than hidden.

Illustrative: the company behind this package#

Illustrative: Tallis Ridge Electronics is a fictional EMS provider that builds printed circuit board assemblies for industrial control, instrumentation and test equipment customers. Quotes, jobs and purchasing run through its ERP, a separate BOM quoting tool handles part cleansing and component pricing, and an MES scans each panel through placement, reflow, AOI and test.

Over the years, Tallis Ridge kept the cleaned BOM next to every original customer BOM, logged estimator corrections and stored AOI operator verdicts and test logs against panel serial numbers. Its NCRs live in a QMS that references work order numbers, so a yield problem can be traced back to the quote and the BOM revision that was built.

The owner wanted to know whether those records could be licensed without exposing a single customer design. The decision, described below, was to license the workflow records and keep every design file, schematic and controlled program out.

The illustrative manifest, file by file#

The manifest lists each file in the package, what one row represents, the fields that matter and the keys that join it to the rest. Every file uses masked customer and program codes, so joins survive even though customer names do not.

How one board travels through the records#

One board travels through the package as a chain of IDs, and following a single chain is the fastest way to test whether a package holds together. A reviewer picks a work order, walks it backward to the RFQ and forward to the yield summary.

• 1RFQ: a masked customer sends a BOM for a motor controller board with several quantity breaks, and rfq_header records the request.
• 2Scrub: the quoting tool flags an obsolete voltage regulator and part numbers missing packaging suffixes, and scrub_corrections stores each fix with its reason.
• 3Quote: the estimator issues a revision that proposes an alternate regulator and adds stencil and fixture NRE, and quote_versions keeps both revisions.
• 4Decision: the customer accepts the second revision, and quote_outcomes records the win and the stated reason, a shorter lead time.
• 5Build: work_orders shows the BOM revision actually built, including the alternate, and the routing through placement, reflow and selective solder.
• 6Inspect and test: aoi_review holds each call and verdict, and test_results holds in-circuit and functional results by board serial.
• 7Yield: yield_by_lot summarizes the lot, and an ncr_mrb record ties a tombstoning issue to the alternate part's package, closing the loop to the quote decision.

What stays out: customer designs and controlled programs#

Customer designs stay out of the package entirely. Gerber and ODB++ files, schematics, assembly drawings, centroid files and the customer's own part numbering belong to the customer, while the workflow records describe what the EMS company did with a design and can usually be separated from it.

Export control needs a separate pass, because export rules may apply to build records as well as drawings. Under the ITAR, technical data includes information required for the design, production, assembly, testing or repair of defense articles, including blueprints, drawings, photographs, plans and documentation, so an EMS provider with defense customers removes those programs completely.

Customer agreements decide the rest. Some restrict any use of information received from the customer, some are silent on workflow records and a few give the customer rights in production data, so counsel reads them program by program and unclear programs wait for a later package.

Documentation that travels with the files#

Documentation that travels with the files explains how the records were produced, what was changed and what was removed, so a buyer can judge the package without asking for raw data. The idea has an electronics lineage: the Datasheets for Datasets proposal borrowed the industry's habit of shipping every component with a datasheet and applied it to datasets.

• 1Data dictionary: every field, its type, its source system and any transformation applied.
• 2Link map: which keys join which files, and how many records lack a link.
• 3Exclusion log: every program, customer, field and file type removed, with the reason.
• 4Coverage note: the years and product families included, and known gaps such as the period before the MES went live.
• 5Process glossary: internal names for stations, defect codes and dispositions.

How SourceX would take this package through review#

SourceX would take a package like this through the SourceX five-step transaction: Supply, Rights, Preparation, Approval and Delivery. The fit check at the Supply step uses metadata only, such as systems, record families and years of accessible history, and no files move until the supplier decides to proceed.

Rights review is where an EMS package usually changes shape, because customer agreements and export control decide which programs remain. Preparation removes personal and confidential details, including operator names and customer identifiers, and the SourceX Evidence Packet records provenance, licensing rights, permitted use, the privacy record and the release authorization.

The supplier approves the final file list before anything is delivered. The records are licensed, not sold outright, and the EMS provider keeps ownership.