Systems Engineering Principles Applied to Any Development Domain

A critically missing process in many software development projects, especially Agile development projects, are the principles of Systems Engineering.

Where I work most often, Systems Engineering dominates the program management and development paradigm. Space Flight, Embedded Systems, Software Intensive System of Systems, Process Control Systems, Safety and Security Systems, Intelligence Systems.

Systems Engineering is the engineering discipline that focuses on the whole system, a set or arrangement of things so related or connected as to form a unity or organic whole. Systems engineering accounts for the connections and interactions among the system functions and with the system environments. This includes physical, social, and logical interrelationships and environments.

In these domains, there are 12 principles used to increase the probability of of success based on Systems Engineering. These principles come from Section 3.2 of?Engineering Elegant Systems: Theory of Systems Engineering, A White paper by Michael D. Watson, NASA Marshall Space Flight Center, June 2020.

Principle 1: Systems engineering integrates the system and the disciplines considering the budget and schedule constraints.

Principle 2: Complex Systems build Complex Systems.

Principle 3: The focus of systems engineering during the development phase is a progressively deeper understanding of the interactions, sensitivities, and behaviors of the system:

• Sub-Principle?3(a): Requirements and models reflect the understanding of the system
• Sub-Principle 3(b): Requirements are specific, agreed to preferences by the developing organization
• Sub-Principle 3(c): Requirements and design are progressively defined as the development progresses
• Sub-Principle 3(d): Hierarchical structures are not sufficient to fully model system interactions and couplings
• Sub-Principle 3(e): A Product Breakdown Structure (PBS) provides a structure to integrate cost and schedule with system functions

Principle 4: Systems engineering has a critical role through the entire system life-cycle:

• Sub-Principle 4(a): Systems engineering obtains an understanding of the system
• Sub-Principle 4(b): Systems engineering models the system
• Sub-Principle 4(c): Systems engineering designs and analyzes the system
• Sub-Principle 4(d): Systems engineering tests the system
• Sub-Principle 4(e): Systems engineering has an essential role in the assembly and manufacturing of the system
• Sub-Principle 4(f):?Systems engineering has an essential role during operations and decommissioning

Principle 5: Systems engineering is based on a middle-range set of theories:

• Sub-Principle 5(a): Systems engineering has a physical/logical basis specific to the system
• Sub-Principle 5(b): Systems engineering has a mathematical basis
• Sub-Principle 5(c): Systems engineering has a sociological basis specific to the organization

Principle 6: Systems engineering maps and manages the discipline interactions within the organization.

Principle 7: Decision quality depends on the coverage of the system knowledge present in the decision-making process.

Principle 8: Both Policy and Law must be properly understood to not overly constrain or under constrain the system implementation.

Principle 9: Systems engineering decisions are made under uncertainty accounting for risk.

Principle 10: Verification is a demonstrated understanding of all the system functions and interactions in the operational environment.

Principle 11:?Validation is a demonstrated understanding of the system’s value to the system stakeholders.

Principle 12:?Systems engineering solutions are constrained based on the decision timeframe for the system need.

These Principles are enabled by 7 Postulates

Postulate 1: Systems engineering is system specific and context dependent in application.

Postulate 2: The systems engineering domain consists of subsystems, their interactions among themselves, and their interactions with the system environment.

Postulate 3: The function of systems engineering is to integrate engineering and science disciplines in an elegant manner.

Postulate 4: Systems engineering influences and is influenced by organizational structure and culture.

Postulate 5: Systems engineering influences and is influenced by budget, schedule, policy, and law.

Postulate 6: Systems engineering spans the entire system lifecycle.

Postulate 7: Understanding of the system evolves as the system development or operation progresses.

Postulate 7 Corollary: Understanding of the system degrades during operations if system understanding is not maintained.?

Systems Engineering Principles Applied in the Agile Development Domain

In some recent exchanges about the "12 Agile Principles," Thoughts on the Agile Manifesto, Agile at Scale and the Agile Manifesto and Principles in Federal Acquisition, and the Manifesto Agile Development in Federal Acquisition there is no consideration from the most vocal agile advocates on the systems engineering principles that frame all software development that operate on the far left side of the Paradigm of Managing an Agile Development Project - since all software development use, produces, and results in a System.

The basis of that understanding starts in the Guide to the Systems Engineering Body of Knowledge - in System Life Cycle Process Models: Agile Systems Engineering and the section titled "principles of agile development"

Along with that are 6 guides for applying Agile Development in the US Department of Defense (one of my domains)

1. Agile Development and DoD Acquisition
2. Agile Culture in the DoD
3. Management and Contracting Practices for Agile Programs
4. Agile Acquisition and Milestone Reviews
5. Estimating in Agile Acquisition
6. Adopting Agile in DoD IT Acquisitions