Numbering Systems

Numbering Systems--General

This section provides criteria for the development of numbering systems for engineering documents. Criteria is also provided for numbering systems for model identification, specifications, and standards. In addition, serial numbering and cataloging are covered.

There is no simple way, nor is there any one kind of numbering system, universally applicable to the variety of products manufactured in this country. Clearly, whichever method is used or type of numbering system is applied must be tailored to the product that is to be identified. It is the purpose of the following sections to provide the user with criteria for determining what kinds of systems are most suitable to their needs.

It should be kept in mind that whatever numbering system is established will be used by many individuals in and out of the company. It is therefore imperative that, to the extent possible, the system be designed to accommodate the needs of all who will be impacted. In addition, the system should provide for growth.

Prior to implementation, the system you select should be extensively tested. Dry run its various uses, revisions, and expansion capabilities to be certain that it will indeed accommodate your needs.

The control of numbering systems should be administered from a single point within the company. That focal point should preferably reside in the drafting or engineering function or any other function deemed appropriate by management.

In order to maintain engineering and manufacturing records so that service may be provided for products, it is necessary to positively identify products and their component parts. Accurate records must therefore be maintained. Drawings, specifications, producing tools, and so on must be systematically numbered so that there will be no duplication.

Numbers for model designations, drawings, specifications, standards and catalogs must be readily recognizable as such and not be able to be confused with other identification numbers. Depending upon how such numbers are used, they may be adaptable for various applications. For example, a model designation and a drawing number may be used as catalog numbers; a drawing number may be adaptable for pattern, mold, tool and die numbers, and so forth.

Numbering Systems--Structures

Before a company commits itself to a drawing numbering system it should consider the applicable following points:

  1. Scope of product is basic noncomplex design, standardized, with minimum variations.
  2. Scope of product is basic complex design with many variations, a range of sizes and configurations, many tailored features provided at clients’ requests.
  3. Scope of product is highly customized to clients’ needs, complex basic design.
  4. Scope of product is aimed primarily to consumer marketplace.
  5. Scope of product is aimed at industrial and military users.

The above points are not all-encompassing. Therefore it is possible that a combination of the scopes may more nearly fit the corporation’s needs for a numbering system. The numbering system structures that follow are intended to fill such needs as far as is practical.

The drawing revision letter or number should never be used with a drawing number unless the abbreviation REV following the number is used (for example, 101K999 REV. A).

If desired, drawing numbering systems may include drawing sheet sizes with the number, provided the number base is sufficiently large to last 20 to 30 years. Such an inclusion will limit the size of the number series. The letter size is not essential; however, as long as drawing forms with title blocks that include drawing size block are used.

It is essential that an accurate drawing log assignment record be kept at all times. As a minimum, the log should show the number and assignment data, such as the drawing number, to whom and the date the drawing was assigned, and the date of issue of the drawing or document.

Several Numbering Systems Detailed

Many drawing numbering systems lack organizational qualities, which should form the basis for what kind of numbering systems are best suited to the company. In fact, many are frequently developed to satisfy an immediate need, with little thought given to their fundamental purpose, control, expandability, mnemonic characteristics, and manipulation in an automated data-processing system. To meet such needs, the following ideas are provided as a guide for the design of drawing numbering systems. Both significant and nonsignificant numbering systems are covered.

Numbering Systems--Selected Examples

In prior sections some guidelines and recommendations have been provided for the development of numbering systems for various documents produced and controlled by the engineering/drafting functions, in addition to model numbers. The publishers of the Drafting Manual believe it to be in the best interests of the subscribers to be cognizant of other number systems. After reviewing more than two thousand numbering systems, the following examples were selected for informational use. They cover significant, nonsignificant, and combinations of both sets of attributes. They are not intended as recommendations. Rather, they are provided as demonstrable practices in the structure of numbering systems designated to identify various kinds of products.

Commercial and Governmental Entity (CAGE) Code

The Commercial and Governmental Entity (CAGE) is a 5- or 6-digit code for domestic or foreign manufacturers who have supplied products to the Federal Agency (usually military) that is generally responsible for designing a product, a specification, or a system. These codes may appear in such agencies’ drawings and specifications. They are assigned in conformance to Cataloging Handbook H8. This publication is the result of combining prior books issued under the name "Federal Supply Code for Manufacturers" (FSCM).