Systems Integration - Revisiting the Definition of an Old Friend

What is Systems Integration? How does one define it? Sometimes, in order to understand what something is, we must first understand what it is not.  Systems Integration is not a box drawn at the end of a life cycle that instructs us to put the system together.  Systems Integration isn’t something a contractor puts on their business card to obtain consulting work.  Systems Integration is not a point in the life cycle but a continuum.  Systems Integration is not only concerned with the integration of hardware and software but of processes and specialties as well.

One of the goals of Systems Integration is to achieve customer satisfaction.  The word integration is related in its root to other words such as integer and integral.  These words speak of a “whole” not a part.  Systems Integration, therefore, is related to the whole, throughout, and not just part of the system life cycle.  One is integrating all of the specialties throughout the life cycle and not only at the end of the life cycle.  Systems Integration is a synthesis.  To integrate is to merge into a whole, to complete, to combine, to make harmonious or to orchestrate.  Integration is a blending or a uniting.

Systems Integration is involved with the requirements as well as architecture.  Integration of design requirements is part of the system engineering process.  The rigor imposed by a formal systems engineering process ensures that all of the specialty disciplines respond to requirements in a timely and integrated manner.  Systems Integration involves architecture also.  One takes all of the pieces and puts them together somehow to yield a functioning system that accomplishes the requirements.  Part of this “putting together involves interface definition and control early in the program for successful and on schedule development.  This putting together is Systems Integration.  Systems Integration is not only new development but COTS and re-engineering.

In attempting to understand Systems Integration, one can begin by first examining some definitions of Systems Engineering.  One finds that the concept of Systems Integration is embedded as a component of these definitions of Systems Engineering.  First, the old MIL-STD-499A defines systems engineering as:

The application of scientific and engineering efforts to (a) transform an operational need into a description of system performance parameters and a system configuration through the use of an iterative process of definition, synthesis, analysis, design, test, and evaluation; (b) integrate related technical parameters and ensure compatibility of all physical, functional, and program interfaces in a manner that optimizes the total system definition and design; (c) integrate reliability, maintainability, safety, survivability, human engineering, and other such factors into the total engineering effort to meet cost, schedule, supportability, and technical performance objectives.

The Defense Systems Management College defines systems engineering as follows:

“Systems engineering is the management function which controls the total system development effort for the purpose of achieving an optimum balance of all system elements.  It is a process which transforms an operational need into a description of system parameters and integrates those parameters  to optimize the overall system effectiveness.

The International Council on Systems Engineering (INCOSE) includes as part of their definition of Systems Engineering as integrating  “all disciplines and specialty groups into a team effort forming a structured development process that proceeds from concept to production.”

Although these are definitions of Systems Engineering, pieces of the definition contain references to Systems Integration.  Extracting from these definitions, integration seems to contain the elements of compatibility, optimization, interface, totality and effectiveness.   Systems Integration is what achieves optimization.  According to MIL-STD-499A, systems integration ensures “the compatibility of all physical, functional, and program interfaces in a manner that optimizes the total system definition and design.” Both the MIL-STD-499A and INCOSE definitions speak, not only of product integration, but also of integrating disciplines into a total engineering effort.  At a minimum, then, the aforementioned elements should be contained in a proposed definition of systems integration.  Furthermore, one must answer the question, what is the end or goal of systems integration?  In other words, why are we doing it?  The answer is to satisfy the objectives or requirements levied on us, to meet cost and schedule objectives, and to optimize the effectiveness of our system.  The elements of operating together and interfaces must be included in our definition of Systems Integration as well.

Therefore, borrowing some of the phraseology from the above stated definitions of systems engineering, my proposed definition of Systems Integration would be as follows:

Systems Integration is a process or a set of actions which ensures that the elements of a system are compatible and function together such as to satisfy the requirements, meet cost and schedule and optimize the effectiveness of the system.  It ensures the compatibility of all physical, functional, and program interfaces in a manner that optimizes the total system definition and design.  It amalgamates all disciplines and specialty groups (i.e., reliability, maintainability, safety, survivability, human engineering, and others) into a total engineering effort to meet cost, schedule, supportability, and technical performance objectives.