Source Control Drawing

Sarah
DeGuzman

A source control drawing provides manufacturing detail for a single-sourced item. In this article, you will learn what unique attributes a source control drawing contains, the applicability of ASME y14.24, and the use of a source control drawing vs. a specification (or vendor) control drawing.

Unique Attributes of a Source Control Drawing

A Source Control Drawing is a type of technical drawing used to fully and clearly present the functions and performance standard for acquiring items and vendor-created items from specific areas within an industry without informing on intellectual property around design.

A sample form of Source Control Drawing
Courtesy: StudyLib

Also, it provides an engineering description (including configuration, part number, marking, reliability, environmental, functional / performance characteristics), qualification requirements, and acceptance criteria for commercial or vendor-developed items procurable from a specialized industry segment that provides for applying critical or unique features.

Applicability of ASME y14.24

This standard describes most of the engineering drawings that determine engineering requirements. It outlines typical applications and minimal content specifications. This standard does not cover the drawings for specific engineering fields such as marine, civil, building, optics, etc.

ASME logo
Courtesy: Wikipedia

Here’s what ASME y14.24 has to say about Source Control Drawings:

10.3 Source Control Drawing

10.3.1 Description

A source control drawing gives an in depth description of a commercially created item in engineering standards. They are from special segments of an industry and offer performance, installation, interchangeability, or other characteristics
required for critical applications. The drawing provides a list of approved sources of supply and the how they are identified for the item(s) that have been qualified and approved for use in the critical application(s). The source control drawing establishes the source control item identification.

10.3.2 Application Guidelines

10.3.2.1 A source control drawing provide

(a) a means of establishing engineering requirements for selecting, qualifying, and acquiring an item from commercial sources.
(b) identification of the items/sources qualified to meet the stated requirements for the specific critical
application.
(c) documentation to ensure the interchangeability of specified items in the stated application each time
acquired.
(d) coverage of source-controlled items developed at private expense where the design is control by the originating design activity. It is not the intent of a source control drawing to define a complete design disclosure.
(e) an item identification, i.e., the source control drawing number and applicable suffix identifier, along with the DAI, for each qualified and approved item.

10.3.2.2 A source control drawing shall not be used to delineate

(a) an item that does not require qualification in advance of a procurement action. If qualification is not
required, the item is normally a candidate for vendor item control drawing coverage.
(b) an altered item, selected item, or item delineated by a nationally recognized standard unless, in the latter case, qualification for the specific application(s) is required.

10.3.3 Requirements

A source control drawing discloses sufficient information to ensure the identification and reprocurement of acceptable items.
NOTE: Preparation requirements for a source control drawing are identical to a vendor item control drawing except for the identification of critical application(s), qualification and approval requirements, item identification, approved sources of supply in lieu of suggested sources of supply, and required notation.

10.3.3.1 The drawing includes, as applicable
(a) requirements of a vendor item control drawing specified in para. 10.2.3.1.
(b) qualification and approval requirements. Successful completion of qualification test requirements establishes a new item identification for the qualifying item.
(c) an identifier assigned to the qualifying item.
(d) reidentification marking requirements; the original item identification being replaced shall not be removed or obliterated. The reidentification markings shall be in addition to the existing original marking and be visibly separate from and in no way interfere with the existing markings. The source control identification shall include a DAI (e.g., CAGE Code, the notation SOCN, and the PIN).

10.3.3.2 The drawing shall include
(a) the vendor and item identification for each item that has been qualified and approved for use, listed
under the heading APPROVED SOURCES OF SUPPLY. Two or more sources are desirable.
(b) identification of the specific critical application for which the item is approved.

(c) the following notes:
ONLY ITEMS DESCRIBED ON THIS DRAWING ARE APPROVED FOR USE IN THE APPLICATIONS
SPECIFIED HEREON. A SUBSTITUTE ITEM SHALL NOT BE USED WITHOUT PRIOR APPROVAL BY THE
QUALIFYING ACTIVITY. IDENTIFICATION OF THE APPROVED SOURCES OF SUPPLY HEREON IS NOT TO BE CONSTRUED AS A GUARANTEE OF PRESENT OR CONTINUED AVAILABILITY AS A SOURCE OF SUPPLY FOR THE ITEM DESCRIBED ON THE DRAWING.
(d) the notation SOURCE CONTROL DRAWING placed adjacent to the drawing title block

Use of a Source Control Drawing vs. Specification Control Drawing

Engineering drawings with tools
Courtesy: MCL Industries

Source Control Drawing differs from Vendor Item Drawing, (Specification Control Drawing). Here are some instances of how they differ:

Standard Source Control DrawingSpec Control Drawing
ApplicationTypically used for items that are customized, custom-designed, and fabricated by a supplier upon request of one customer.Typically used for commercial off-the-shelf components selected by a customer’s engineer for use in one or more products.
RequirementsCritical, known, requirements are defined. Typically, however, there are characteristics that might affect performance, but cannot be fully anticipated or specified.Most of all public information about the item is included in a vendor item drawing, which is sufficient for the customer engineer to decide on its selection. It is also sufficient for selecting an alternate, such as in the case of the original item being obsoleted by the manufacturer. Note that a complete portrayal of the design is not generally intended or possible, and therefore the item cannot usually be reproduced using only the vendor item drawing. The manufacturer data sheet, MSDS, catalog page, etc. form most of the vendor item drawing content, including, as applicable:
a. Performance, operating, and other functional characteristics
b. Schematic information
c. Mounting, interface characteristics, envelope dimensions, and tolerances
d. Maintainability, reliability, life, environmental characteristics
Qualification ProcedureThe qualification procedure must be defined.The qualification procedure is not applicable.
Acceptance CriteriaIt is defined on the drawing if the appropriate criteria are not obvious to a manufacturing engineer.It is defined on the drawing if the appropriate criteria are not obvious to a manufacturing engineer.
Part NumberIt is defined and listed on the drawing.It is defined and listed on the drawing.
Sources of SupplyApproved sources of supply and their P/Ns for each item are listed.Suggested Sources of Supply, including the supplier’s item identification number (i.e. P/N) corresponding to our part number. The customer’s procurement activity (i.e. the buyer) without prior approval from the engineer, may procure the item from any of the suggested sources, or, from sources not listed.