Illustrated Parts Breakdown (IPB) publications are an important source of information, particularly for ordering specific support-equipment parts. Used properly, they provide the information necessary to identify a part number. In some cases, IPBs provide cross-reference data that can be used when the prime item requested is not in stock.

An IPB is prepared by the manufacturer for most major items of imaging equipment and accessories. The IPB is designed to enable supply and maintenance personnel to identify and order replacement parts for equipment. Procurable assemblies and detail parts are illustrated and listed for quick identification of assemblies and their component parts. The items are arranged continuously in assembly breakdown order. The illustrations are placed as near as possible to their appropriate listing fig 5-6.

Although slight variations in format exist among the various IPBs, each one includes the following major sections:

The INTRODUCTION includes general information about the equipment, contents of the publication, and instructions for use. You should refer to the introduction before attempting to use an unfamiliar IPB.

The GROUP ASSEMBLY PARTS LIST consists of a breakdown of the complete unit into major components, systems, installations, assemblies, and detail parts. Generally, parts are indexed in disassembly order. In some instances, assemblies or installations are shown in assembled form in one figure and the detail parts are illustrated in another figure.

The NUMERICAL INDEX lists part numbers in alphanumerical order, and each part number is cross-referenced to the figure and index number where it is shown. This section also shows the total quantity of each part used in the equipment, material source code, and NSN, when applicable.

The REFERENCE DESIGNATION INDEX lists, in alphanumerical order, reference designators (example: Bl, Jl, K7, and so on) on schematic and wiring diagrams. The index also lists part numbers and index numbers to indicate where the parts are located in the IPB.

CONSOLIDATED MASTER CROSS-REFERENCE LIST

The Consolidated Master Cross-Reference List (C-MCRL) is designed to provide a cross-reference from a reference number, such as a manufacturer's part number, a drawing number, a design control number, and so on, to an assigned NSN. Part I of the C-MCRL is designed to assist you in identifying items in the

Figure 5-6.-Illustrated Parts Breakdown.

Figure 5-7.-Columns of the Consolidated Master Cross-Reference List, part I and part II.

supply system. Part II includes supply items that are used by all military services; therefore, many NSNs will be identified in the C-MCRL that are not listed in the Management List-Nav fig. 5-7.

The information obtained in part I of the C-MCRL is shown in table 5-1

The Reference Number Variation Code (RNVC) row indicates (by use of the numbers 1,2,3, and 9) those items that require supplementary data to identify them fully. These codes are as follows:

Code 1 -Nonidentifying-The reference number does not completely identify the item. When the reference number is cited, it must be accompanied by additional descriptive data, such as color, length, and rating.

Code 2-Identifying-The reference number in company with the Federal Supply Code for Manufacturers (FSCM) completely and uniquely identifies the item of supply. Code 2 items may also have nonidentifying reference numbers.

Code 3-The reference number is a vendor's number or a Source Control Item.

Code 9-This code is used to indicate (1) the reference number is for information only and (2) the reference number or specification is obsolete or superseded.

Table 5-1-Part I of the Consolidated Master Cross-Reference List

Part II of the C-MCRL presents the same data in National Item Identification Number (NIIN) sequence.

OBTAINING MATERIAL

Once you have found the stock number, you are read to requisition supplies. Most material is obtained by requisition, but purchase is used to procure non-standard material or to meet emergency requirements. The simplest form of a requisition is merely a request for material made out on the appropriate Navy form and drawn at a naval supply activity. If material must be obtained by open purchase to fill specialized needs, this also is usually handled by the local supply department or activity.