1. The Architecture of Systems

2. System Architecture Every human-made and natural system is characterized by a structure and framework that supports and/or enables the integrated elements of the system to provide the system’s capabilities and perform missions. This integrated framework is referred to as the system’s architecture. 1-2

3. Architecture via a Construct Let us introduce the concept of the system element architecture via a construct consisting of two key entities: 1)the SYSTEM OF INTEREST (SOI) 2)its OPERATING ENVIRONMENT. The SOI is composed of one or more MISSION SYSTEM(s) (role) and a SUPPORT SYSTEM (role). The OPERATING ENVIRONMENT consists of: 1)HIGHER ORDER SYSTEMS domain 2)A PHYSICAL ENVIRONMENT domain. 1-3

4. 1-4 THE SYSTEM ARCHITECTURE CONSTRUCT All natural and human-made systems exist within an abstraction we refer to as the system’s OPERATING ENVIRONMENT. Survival, for many systems within the OPERATING ENVIRONMENT, ultimately depends on system capabilities—physical properties, characteristics, strategies, tactics, security, timing, and luck. The systems exhibit a common construct—template— that describes a system’s relationship to their OPERATING ENVIRONMENT.

5. 1-5 Top Level System Architecture Construct When you analyze interactions of a SYSTEM OF INTEREST (SOI) with its OPERATING ENVIRONMENT, two fundamental types of behavior emerge: 1. Hierarchical interactions (i.e., vertical interactions under the command and control of higher order systems). 2. Peer level interactions.

6. System Elements Important for three reasons: First, the system elements enable us to organize, classify, and bound system entity abstractions and their interactions. That is, it is a way to differentiate what is and what is not included in the system. Second, the System Element Architecture establishes a common framework for developing the logical and physical system architectures of each entity within the system hierarchy. Third, the system elements serve as an initial starting point for allocations of multi-level performance specification requirements. 1-6

7. Identification of system element classes by domain 1-7

8. 1-8 Top Level System Environment Construct When a MISSION SYSTEM interacts with its OPERATING ENVIRONMENT, it: 1. Performs mission task assignments established by higher level, chain-of-command, decision authorities. 2. Interacts with external systems (i.e., human-made systems, natural environment, and its induced operating environment during mission execution environment).

9. 1-9 THE SYSTEM ARCHITECTURE CONSTRUCT When systems interact with their OPERATING ENVIRONMENT, two types of behavior patterns emerge: 1. Systems interact with or respond to the dynamics in their OPERATING ENVIRONMENT. These interactions reflect peer-to-peer role-based behavioral patterns such as aggressor, predator, and defender or combinations of these. 2. System Responses—behavior, products, by-products, or services—and internal failures sometime result in adverse or catastrophic effects to the system—creating instability, damage, degraded performance, for example—that may place the system’s mission or survival at risk.

10. Challenge in analyzing The challenge in analyzing and solving system development and engineering problems is being able to identify, organize, define, and articulate the relevant elements of a problem (objectives, initial conditions, assumptions, etc.) in an easy-to-understand, intelligible manner that enables us to conceptualize and formulate the solution strategy. Establishing a standard analytical framework enables us to apply “plug and chug” mathematical and scientific principles, the core strength of engineering training, to the architecture of the system. 1-10

11. UNDERSTANDING SYSTEM ELEMENT ENTITY RELATIONSHIPS System element interactions can be characterized by two types of relationships: Logical physical Perhaps the best way to think of logical and physical relationships is to focus on one topic at a time and then integrate the two concepts. 1-11

12. Identifying Logical Entity Relationships The first step in identifying logical entity relationships is to simply recognize and acknowledge that some form of association exists through deductive reasoning. Graphically, we depict these relationships as simply a line between the two entities. The second step is to characterize the logical relationship in terms of logical functions— that is, what interaction occurs between them—must be provided to enable the two entities to associate with one another as logical architecture. 1-12

13. Logical Association Example: Light Source 1-13

14. Physical Entity Relationships The physical implementation of system element interfaces requires more in-depth analysis and decision making. Why? Typically, cost, schedule, technology, support, and risk become key drivers that must be “in balance” for the actual implementation. Graphically, the physical Implementation as a physical representation. As we select components (copper wire, light switches, lighting fixtures, etc.), we configure them into a system block diagram (SBD) and electrical schematics that depict the physical relationships. These diagrams become the basis for the Physical System Architecture. 1-14

15. Physical Representation 1-15