Altered Item Drawing
As defined by ASME Y14.24, an Altered Item Drawing does exactly what its name says: it modifies some other part by adding and/or subtracting features. The original part is usually under the configuration control of some other design activity (usually a different company) or is the subject of some national standard. This drawing type is... read more
Ancillary Drawing
In the ASME Y14.24 context, any drawing that is not identifying. Ancillary drawings are most often used to document Engineering information that is better understood in graphical form (as opposed to textual), but is not mandatory for the manufacture of the subject part. This concept can confuse Engineers who do not have a strong design... read more
Book-form
A drawing assembled in bound form. It can be A-size or larger. Even though the command media of some companies explicitly prohibits multiple volumes of a book-form drawing, some parts of said companies do it on a regular basis. These volumes are (confusingly) referred to as “sheets”…even though each page of each volume is termed “sheet”... read more
Envelope Drawing (ED)
A type of PCD used when the procuring authority wishes to stipulate certain design features without themselves completing the design. An ED is usually created as the first in a chain of drawings when some or all of the design Engineering effort is to be procured.
Identification Cross-Reference Drawing (ICRD)
A type of Procurement Control Drawing that directs procurement of items from sources (usually commercial) that do not use ASME-compliant product identification, altering the items for part-marking only. The combination of instructions and part-marking effectively incorporates them into an ASME-compliant framework. This drawing type for critical high-performance applications is quite rare, because it is almost impossible to... read more
Index Drawing
A drawing having the sole purpose of pointing to other drawings to create an enumerated list (“index”).
Layout
“A layout drawing depicts design development requirements. It is similar to a detail, assembly, or installation drawing, except that it presents pictorial, notational, or dimensional data to the extent necessary to convey the design solution used in preparing other engineering drawings. Except as noted…a layout drawing does not establish item identification.”1 FootnotesASME Y14.24, section 2.1.[↩]
Level (1|2|3) Drawing
Three “levels” of Engineering Drawing were defined by the now-defunct DOD-D-1000 “Drawings, Engineering and Associated Lists”. Even though the standard is no longer in use, and has not (to my knowledge) been functionally replaced by an industry standard, the “levels” concept is of some use in establishing a mental organization of how design progresses. It... read more
Make-from Drawing
This isn’t actually a formally defined drawing type. It simply refers to a drawing that calls and modifies one or more other parts. If the part was purchased in the configuration from which the modification starts, this drawing could be an Altered Item Drawing. Otherwise, it is simply a non-detail production drawing.
Manufacturing Drawing
A drawing that supplies information for a manufacturing process. These drawings can be either identifying or ancillary. When the manufacturing process is at some significant rate, or under high levels of control, these drawings are sometimes referred to as “production drawings”.
Multi-Purpose Drawing
It is legitimate to have a single drawing that acts as more than a just one drawing type. A good example is to start with an existing item from any one of several different suppliers (see Vendor Item Control Drawing), screen the parts to get only the really good ones (see Selected Item Drawing), then... read more
Procurement Control Drawing (PCD)
A class of drawing, some sub-types of which are identifying, that is used to purchase outside Engineered materiel or Engineering services. PCD types include Envelope Drawings, Source Control Drawings, and Vendor Item Control Drawings. The sub-types evolve in very different ways depending on who pays for different types of associated Intellectual Property.
Production Drawing
A Manufacturing Drawing used for rate production (as opposed to, for example, a one-off).
Selected Item Drawing
As defined by ASME Y14.24, a Selected Item Drawing does exactly what its name says: it selects certain as-built items from a production stream, rejecting others. This drawing type is identifying because the parts meeting its acceptance criteria are no longer interchangeable with any other parts for the purposes that caused the selected item drawing... read more
Sheet-form
Any drawing that is not book-form.
Sketch
A preliminary type of drawing (typically Level II).
Software Installation Drawing (SID)
An identifying drawing that configuration controls software and its installation in a production environment. A SID is often little more than a simple drawing that points to an SVD and assigns a P/N in the production system.
Software Version Description Drawing (SVDD)
In some companies, combines the characteristics of an SVD and a SID into a single drawing type. Not currently found in ASME Y14.24.
Source Control Drawing (SCD)
A type of PCD used for the circumstance where an existing part is sufficient to our design purpose, but new qualification data1 must be paid for by the customer (which may, or may not be, the developer). See also the CI Development Cycle (Intermediate). Footnotes The new data are necessary in order to verify the item’s compliance with a wider... read more
Vendor Item Control Drawing (VICD)
A type of PCD that establishes the acceptability and interchangeability of one or more vendor part numbers for some specific usage. This drawing type permits Procurement and Manufacturing to purchase and install any suitable part. We only (and always) use a VICD when all of the IP (including any qualification data and identifying drawings) are... read more