Key System Characteristics and Performance Parameters

Each system has unique physical and performance characteristics; analysts need specific knowledge about these characteristics before they can develop a cost estimate for a weapon system, an information system, or a construction program.

While the specific physical and performance characteristics for a system will vary from one program to another, several general characteristics have been identified in the various guides we reviewed. Table 5 lists general characteristics shared within several system types. Table 5 is not intended to be exhaustive.

Table 5: General System Characteristics
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System Characteristic
Aircraft Breakdown of airframe unit weight by material type
Combat ceiling and speed
Internal fuel capacity
Length
Load factor
Maximum altitude
Maximum speed (knots at sea level)
Mission and profile
Weight (for example, airframe unit weight, combat, empty, maximum gross, payload, structure)
Wetted area
Wing (for example, wingspan, wing area, wing loading)
Automated information systems Architecture
Commercial off-the-shelf (COTS) software used
Customization of COTS software
Expansion factors
Memory size
Processor type
Proficiency of programmers
Programming language used
Software sizing metric
Construction Ability to secure long-term visas
Changeover
Environmental impact
Geography
Geology
Liability
Location (for example, land value, proximity to major roads, relocation expenses for workers)
Material type (for example, composite, masonry, metal, tile, wood shake)
Number of stories
Permits
Public acceptance
Square feet
Systemization
Missiles Height
Length
Payload
Propulsion type
Range
Sensors
Weight
Width
Ships Acoustic signature
Full displacement
Full load weight
Length overall
Lift capacity
Light ship weight
Margin
Maximum beam
Number of screws
Payload
Propulsion type
Shaft horsepower
Space Attitude
Design life and reliability
Launch vehicle
Mission and duration
Orbit type
Pointing accuracy
Satellite type
Thrust
Weight and volume
Tanks and trucks Engine
Height
Horsepower
Length
Weight
Width
Payload

Source: DOD and GAO | GAO-20-195G

Once a system’s unique requirements have been defined, they should be managed and tracked continually throughout the program’s development. If requirements change, both the technical baseline and cost estimate should be updated so that users and management can understand the effects of the change. Because it is evolutionary, earlier versions of the technical baseline will necessarily include more assumptions and, therefore, more uncertainty. These assumptions should be replaced with information as they become known; consequently, the level of uncertainty associated with the assumptions will decline.