Spare parts provide the means to repair and maintain a product ( In this
reference guide the term "product" refers to the end item for which the
customer is paying. "Product" can range in size from a large intricate system
down through a subsystem, an equipment, or an item. For Government contracts,
"product" could mean an entire weapons system, part of a weapons system, or a
non-military item. "Customer" can be either a Government or civilian procuring
agency. See the Glossary for definitions of these terms.) in its operating
environment. This template explains how to systematically and methodically
determine spares support by using Logistic Support Analysis (LSA) methods and
output information. The essential elements of this template process and how
they work together are shown in the associated graph. (shown below) Each
process step is numbered and referenced by number in the explanatory text of
Each spares situation is unique. Therefore, this template cannot cover all
requirements for spares determination. Only key requirements and activities
are discussed. The reader should consult any applicable directives to ensure
compliance with a particular contract.
The items determined by this template process fall into three
Spares - replaceable items used to effect a repair that are themselves
Repair parts - replaceable items used to effect a repair but are not
Consumables - items like paper and grease used in
the repair process.
Although the discussion in this template focuses on determining spares,
this template process generally applies to all repair parts and consumables as
The logistics elements discussed in this reference guide are interactive.
For example, the level and nature of spares for a particular product
influences and is influenced by:
Product design - especially the diagnostic approach
Technical manuals - the level of detail for maintenance procedures
Manpower, personnel, and training - the level of
skill needed to repair a product with the available spares.
A strong management commitment to determining spares yields substantial
Management support of the spares determination template process also helps
ensure that correct parts are available when needed. The procedures
Defining the basic spare parts needs through product reliability and the
Allocating specific repair activities through Level of Repair analysis
Matching spares needs to existing repair facilities and the skill level of
the personnel at those facilities
Defining spares through customer guidance statements and
- Comparing the recommended spares to available
- Purchasing new spares.
Note, do not complete spares analysis before the system design is stable to
avoid wasted effort.
Determining spare parts, and purchasing and maintaining those spare parts,
is costly. Historically, money for these activities is not available at the
right time. Often purchasing spare parts is not addressed until late in a
product design and development program. Sometimes there is no process of
spares determination at all. This leads to such problems as:
Products sitting idle while waiting for repair parts
The wrong part at the wrong place
Not using the available maintenance support to the fullest
Not understanding or considering how environmental, transportation,
facility, or other factors affect spares
Disagreement between spares, technical manual
procedures, and training information.
As well as the obvious expense of stocking the wrong spare parts, hidden
costs result from neglecting the spares determination template
The spares determination template process has two basic