Ultra-large-scale Systems - Characteristics of An Ultra-large-scale System

Characteristics of An Ultra-large-scale System

Ultra-large-scale systems hold the characteristics of systems of systems (systems that have: operationally independent sub-systems; managerially independent components and sub-systems; evolutionary development; emergent behavior; and geographic distribution). But in addition to these, the Northrop report argues that a ULSS will:

• Have decentralized data, development, evolution and operational control
• Address inherently conflicting, unknowable, and diverse requirements
• Evolve continuously while it is operating, with different capabilities being deployed and removed
• Contain heterogeneous, inconsistent and changing elements
• Erode the people system boundary. People will not just be users, but elements of the system and affecting its overall emergent behavior.
• Encounter failure as the norm, rather than the exception, with it being extremely unlikely that all components are functioning at any one time
• Require new paradigms for acquisition and policy, and new methods for control

The Northrop report states that "the sheer scale of ULS systems will change everything. ULS systems will necessarily be decentralized in a variety of ways, developed and used by a wide variety of stakeholders with conflicting needs, evolving continuously, and constructed from heterogeneous parts. People will not just be users of a ULS system; they will be elements of the system. The realities of software and hardware failures will be fundamentally integrated into the design and operation of ULS systems. The acquisition of a ULS system will be simultaneous with its operation and will require new methods for control. In ULS systems, these characteristics will dominate. Consequently, ULS systems will place unprecedented demands on software acquisition, production, deployment, management, documentation, usage, and evolution practices."