No two are the same. Whether they label ballpoint pens, combat boots or spare parts, National Stock Numbers have become the axis of federal supply. Take them away and the systems and processes used to manage materiel would come to a halt.
“If NSNs somehow disappeared, we’d be in big trouble. We could still place and fulfill orders based on the manufacturer’s part number, but managing those items through the supply chain would be a time-consuming process because our logistics systems and those of the services are all designed around NSNs,” said Raymond Zingaretti, director of Logistics Information Services for Defense Logistics Agency Logistics Operations.
NSNs are 13-digit codes assigned to every item repeatedly bought, stocked, used, distributed and disposed through the federal supply system. More than just a long number, NSNs are a gateway to information like the item’s manufacturer, dimensions and cost – all critical details for logisticians who manage military supplies throughout their life cycle.
Birth of the NSN
NSNs were created after World War II when officials realized that similar items used by more than one military service had multiple names and part numbers, making it difficult for the services to share supplies. Washers, for example, were also commonly called shims and spacers. While one service used the term “washer” and gave it their own unique stock number, other services gave it different names and created their own unique stock numbers. The different naming conventions made it seem as if one unit or service had plenty in stock while another had none, resulting in duplicate purchases.
In 1952, Congress approved the Defense Cataloging and Standardization Act to improve the services’ ability to share supplies, and in 1998, DLA assumed cataloging of all Department of Defense supplies whether managed by the services or DLA. Standardizing the name of items with the same form, fit and function under a single NSN led to better visibility and control of supplies while also decreasing prices, Zingaretti said.
“When you give unique stock numbers to multiple versions of essentially the same part, you lose your ability to drive competition among suppliers and drive down the cost. It also creates the need for additional warehouse space because you’ve got to store the items in multiple bins,” he said.
Today there are over 7 million NSNs. Zingaretti’s staff of almost 350 catalogers in Battle Creek, Michigan, create about 70,000 new NSNs each year at the request of the services and equipment program managers using data like the item name, manufacturer’s part number, unit price, physical and performance characteristics, special-handling instructions, shelf life and disposal procedures. Those NSNs and the accompanying data are stored and routinely updated in the Federal Logistics Information System.
Creating New NSNs
NSN creation usually starts before the rollout of a new weapon system when program managers, suppliers and DLA representatives are outlining all the pieces that make up the system. This careful review is conducted so planners can ensure spare parts are available throughout the system’s life cycle.
“During this provisioning process we determine how we’re going to sustain materiel in the long run. It’s essentially a supportability analysis to determine what parts on the system we’re going to fix, what parts we’re going to throw away and which parts we need for repairs,” Zingaretti said.
The result is a list of items that already have NSNs because they’re used on other systems and a list of parts that need to be assigned NSNs and uploaded in FLIS with details in 25 or more categories, such as dimensions and material make-up.
“Our goal is to describe the item fully so the services know what they’re getting,” said Michael Plants, a logistics data cataloger who processes data and NSNs for valves. “A ball valve, for example, has a body, stem, ball and flow-control device. I identify all of the materials of those products so the services know what each individual part is made of.”
Knowing the material can be critical in cases where only one type of metal is approved for use on a particular vehicle, aircraft or ship, he added. Other characteristics he includes are operating pressures and temperatures, as well as the connection type. Though it usually takes about one hour for Plants to create an NSN for a new valve, sometimes catalogers have to spend hours analyzing manufacturers’ drawings to decipher details like dimensions.
“Interpreting drawings is a very difficult and time-consuming process, and that’s why we spend part of the 12 to 18 months it takes to train new catalogers teaching them how to read technical drawings,” Zingaretti said.
Adding descriptions in areas such as demilitarization and safety is another challenge because FLIS, which was developed in the 1990s, requires users to input codes, a practice that’s earned catalogers the nickname “code talkers.” Logistics Information Services is developing a plan to update FLIS with current technology.
“It would be easier to have a drop-down menu with options like ‘sell to the public’ rather than code ‘A,’ which you’ve got to remember the meaning of or continually look up,” Zingaretti added.
Breaking Down the Numbers
Like telephone numbers with separate sections for the area code, exchange and unique four-digit number, NSNs are made up of four distinct parts with each separated by a hyphen. The first four digits are the Federal Supply Group and the Federal Supply Class, both of which organize supplies into logical families. Construction and building materials make up supply group 56, for example, and items that fall into that category are subdivided into supply classes, such as 5620 for tile, brick and block. There are 78 supply groups and 645 classes in all.
The next two digits depict the country of origin code, such as “00” and “01” for the United States. The final seven digits are the Unique Serial Number, a sequential number automatically generated by FLIS. The country code and Unique Serial Number together are known as the National Item Identification Number.
“In areas like order management, distribution and disposition, the NIIN can be used to refer to a part. It’s a shorthand way of identifying what the item is,” Zingaretti said.
But the first four numbers are sometimes used by material handlers to determine whether an item needs special handling. Employees at DLA Distribution and DLA Disposition Services sites must be able to recognize whether an item is nuclear-weapons-related material, for example, because regulation requires that it be returned to the Air Force immediately upon discovery.
DLA will begin cataloging parts for the new B-21 Raider in 2019. The provisioning, cataloging and acquisitioning process is expected to take about seven years, Zingaretti said, adding that DLA’s goal is to input all data in FLIS before the first aircraft is delivered.
In September, catalogers completed data entry and NSN assignment for over 52,000 parts for the new F-35 Lightning II. Though cataloging is normally done before unit equipping, as is expected with the B-21, the initial supply support concept for F-35 parts put stocking, storing and distribution in the hands of manufacturers.
“Everything was going to be run by contractors so there was no need to catalog the items. But then these parts started showing up in our disposition yards and DLA Disposition Services folks had no data on these parts whatsoever because they hadn’t been cataloged,” Zingaretti said.
DLA began cataloging the parts so disposal experts had the information necessary to properly strip defensive capabilities of excess material from the fighter jet simply by referring to the demilitarization code associated with the NSN. Demilitarization codes indicate the degree of destruction required before an item can be disposed of.
Requests for new NSNs also occur when the services repeatedly order new items. Although NSNs generally live forever after they’re created, catalogers like Kristin Truex dedicate their days to updating data in FLIS.
“DLA product specialists may ask us to change a part number or update a source because there’ve been manufacturing changes, or we might need to update characteristics of an item,” she said, adding that cataloging is more than just data entry.
“We also do a lot of research. For instance, if we’re updating technical data from a new drawing and notice one of the codes has changed, it’s our job to review it and make sure the code is correct,” Truex said.
Though most troops may think of the NSNs on their equipment as just official labels, catalogers and logisticians view them as a link to critical data needed to support supplies from the time they’re purchased until they’re disposed of, Zingaretti added.
“The real power of the NSN is that other than cataloging items into segments and providing a way to identify supplies the same way across the services, it gives us a common language for planning, procurement, warehousing, distribution, repair and disposition,” he said.