Computer Engineering


Okon, Walt, Computer Engineering -   Distinction between Architecture and Systems Engineering    12 September 2006
Point Paper
Distinction between Architecture and Systems Engineering
Prepared By: Walt Okon
12 September 2006

What Is Systems Engineering?

1.  Systems Engineering is an interdisciplinary approach and means to enable the realization of successful systems. It focuses on defining customer needs and required functionality early in the development cycle, documenting requirements, then proceeding with design synthesis and system validation while considering the complete problem:

    Operations
    Performance
    Test
    Manufacturing
    Cost & Schedule
    Training & Support
    Disposal

Systems Engineering integrates all the disciplines and specialty groups into a team effort forming a structured development process that proceeds from concept to production to operation. Systems Engineering considers both the business and the technical needs of all customers with the goal of providing a quality product that meets the user needs.

 The above definition is provided byINCOSE, The International Council on Systems Engineering, http://www.incose.org/whatis.html, 



2.  The most important and agreed upon concept is that Systems Engineering is:
           1.    an  interdisciplinary approach
           2.    a means to enable a successful system/systems
           3.    focuses on defining customer needs and required functionality
All of this is enabled by configuration management of an iterative process of definition, synthesis, analysis, design, test, and evaluation.  It integrates the life-cycle balance of system, people, produce and process solutions that meet the customer’s needs/requirements. 


3.  Systems engineering must encompass architecting, design, development and sustainment, recognizing that the future brings opportunities and increased complexity and associated needs for evolution and adaptation as societies, businesses, and organizations become increasingly inter-twined.  Effective System Engineering Practices requires accepted standards for architecting and interface definition to development of robust systems and supporting the development of a state-of-the-art IT enabling environment.  Architecture and Capability models serve as an enabler for the evolution and integration of an enterprise from a process perspective. 

The engineering of systems will involve strong collaboration and teamwork, and we will see the evolution of the approaches, methods, and tools to drive high levels of effectiveness of a diverse multidiscipline team.


Architecture:

4.  The Architecture and the discipline of architecting is key to delivering the needs/requirements of the customer because it is the architecture that represents the needs of the stakeholders and customers.  It is the architecture that provides the information on which decisions are made by the Pfm manager, Program Managers, Chief Engineer, and Chief Architect.  The Architecture provides the business model that shows the customer what will be delivered so the customer can validate the requirement.  The architecture is the means upon which the design, cost, and schedule estimates can be made.  Therefore, it is the architecture that actually provides the definition of the effort and requirements into objects.  This creates the ability to define component specifications that will be used in the development and implementation.

An architecture description is a formal description of a system, organized in a way that supports reasoning about the structural properties of the system.  It actually defines the system components or building blocks of the system to be built and provides a plan from which products can be procured, and systems developed.  It is the architecture that enables the Director or the program Manager to manage, make decisions and to acquire/investment in a way that meets the defined functional requirements that are defined/showned/realized in the architecture.
Systems architecture can best be thought of as a representation of the engineered (or To Be Engineered) system, and the process and discipline for effectively implementing the design(s) for such a system. Such a system may consist of information and/or hardware and/or software.  It is a representation because it is used to convey the informational content of the elements comprising a system, the relationships among those elements, and the rules governing those relationships.  It is a process because a sequence of steps is prescribed to produce or change the architecture, and/or a design from that architecture, of a system within a set of constraints.  It is a discipline because a body of knowledge is used to inform practitioners as to the most effective way to design the system within a set of constraints.

A system architecture is primarily concerned with the internal interfaces among the system's components or subsystems, and the interface between the system and its external environment, especially the user.


5.  Generally, a neat breakdown of roles and responsibilities among the various types of architects and engineers can't be done, as there are no neat boundaries, but instead a continuous overlap— which is program and people specific. That is, there are no neat boundaries between systems architecture and systems engineering, or between systems engineering and software engineering/architecture.  What we do know is that there is a team relationship between systems engineering and software engineering/architecture.  Each of the team members must play integrated part in the development and delivery of the system/service/product. 


6.  Distinction between Architecture and Systems Engineering is simply that Systems Engineering is the discipline, processes and methods use to deliver a system and the architecture is the ability to actually define the requirements, create the model as real objects, and enable decision making to achieve development and delivey.

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