interdisciplinary
Interdisciplinarity or interdisciplinary studies involves the combination of multiple academic disciplines into one activity (e.g., a research project). It draws knowledge from several other fields like sociology, anthropology, psychology, ec ...
field of
engineering
Engineering is the use of scientific principles to design and build machines, structures, and other items, including bridges, tunnels, roads, vehicles, and buildings. The discipline of engineering encompasses a broad range of more speciali ...
and
engineering management
Engineering management is the application of the practice of management to the practice of engineering.
Engineering management is a career that brings together the technological problem-solving ability of engineering and the organizational, admini ...
that focuses on how to design, integrate, and manage
complex system
A complex system is a system composed of many components which may interact with each other. Examples of complex systems are Earth's global climate, organisms, the human brain, infrastructure such as power grid, transportation or communication sy ...
s over their
life cycle
Life cycle, life-cycle, or lifecycle may refer to:
Science and academia
*Biological life cycle, the sequence of life stages that an organism undergoes from birth to reproduction ending with the production of the offspring
* Life-cycle hypothesis ...
s. At its core, systems engineering utilizes
systems thinking
Systems thinking is a way of making sense of the complexity of the world by looking at it in terms of wholes and relationships rather than by splitting it down into its parts. It has been used as a way of exploring and developing effective actio ...
principles to organize this body of knowledge. The individual outcome of such efforts, an engineered system, can be defined as a combination of components that work in
synergy
Synergy is an interaction or cooperation giving rise to a whole that is greater than the simple sum of its parts. The term ''synergy'' comes from the Attic Greek word συνεργία ' from ', , meaning "working together".
History
In Christian ...
to collectively perform a useful
function
Function or functionality may refer to:
Computing
* Function key, a type of key on computer keyboards
* Function model, a structured representation of processes in a system
* Function object or functor or functionoid, a concept of object-oriente ...
.
Issues such as
requirements engineering
Requirements engineering (RE) is the process of defining, documenting, and maintaining requirements in the engineering design process. It is a common role in systems engineering and software engineering.
The first use of the term ''requirem ...
, reliability,
logistics
Logistics is generally the detailed organization and implementation of a complex operation. In a general business sense, logistics manages the flow of goods between the point of origin and the point of consumption to meet the requirements of ...
, coordination of different teams, testing and evaluation, maintainability and many other disciplines necessary for successful system design, development, implementation, and ultimate decommission become more difficult when dealing with large or complex projects. Systems engineering deals with work-processes, optimization methods, and risk management tools in such projects. It overlaps technical and human-centered disciplines such as
industrial engineering
Industrial engineering is an engineering profession that is concerned with the optimization of complex processes, systems, or organizations by developing, improving and implementing integrated systems of people, money, knowledge, information an ...
,
production systems engineering
Production may refer to:
Economics and business
* Production (economics)
* Production, the act of manufacturing goods
* Production, in the outline of industrial organization, the act of making products (goods and services)
* Production as a stati ...
mechanical engineering
Mechanical engineering is the study of physical machines that may involve force and movement. It is an engineering branch that combines engineering physics and mathematics principles with materials science, to design, analyze, manufacture, ...
,
manufacturing engineering
Manufacturing engineering or production engineering is a branch of professional engineering that shares many common concepts and ideas with other fields of engineering such as mechanical, chemical, electrical, and industrial engineering.
Manufa ...
,
production engineering
Manufacturing engineering or production engineering is a branch of professional engineering that shares many common concepts and ideas with other fields of engineering such as mechanical, chemical, electrical, and industrial engineering.
Manufa ...
,
control engineering
Control engineering or control systems engineering is an engineering discipline that deals with control systems, applying control theory to design equipment and systems with desired behaviors in control environments. The discipline of controls o ...
,
software engineering
Software engineering is a systematic engineering approach to software development.
A software engineer is a person who applies the principles of software engineering to design, develop, maintain, test, and evaluate computer software. The term '' ...
,
electrical engineering
Electrical engineering is an engineering discipline concerned with the study, design, and application of equipment, devices, and systems which use electricity, electronics, and electromagnetism. It emerged as an identifiable occupation in the l ...
,
cybernetics
Cybernetics is a wide-ranging field concerned with circular causality, such as feedback, in regulatory and purposive systems. Cybernetics is named after an example of circular causal feedback, that of steering a ship, where the helmsperson ma ...
,
aerospace engineering
Aerospace engineering is the primary field of engineering concerned with the development of aircraft and spacecraft. It has two major and overlapping branches: aeronautical engineering and astronautical engineering. Avionics engineering is s ...
,
organizational studies
Organization studies (also called organization science or organizational studies) is the academic field interested in a ''collective activity, and how it relates to organization, organizing, and management''. It is "the examination of how individua ...
,
civil engineering
Civil engineering is a professional engineering discipline that deals with the design, construction, and maintenance of the physical and naturally built environment, including public works such as roads, bridges, canals, dams, airports, sewa ...
and
project management
Project management is the process of leading the work of a team to achieve all project goals within the given constraints. This information is usually described in project documentation, created at the beginning of the development process. T ...
. Systems engineering ensures that all likely aspects of a project or system are considered and integrated into a whole.
The systems engineering process is a discovery process that is quite unlike a manufacturing process. A manufacturing process is focused on repetitive activities that achieve high quality outputs with minimum cost and time. The systems engineering process must begin by discovering the real problems that need to be resolved, and identifying the most probable or highest impact failures that can occur — systems engineering involves finding solutions to these problems.
History
The term ''systems engineering'' can be traced back to
Bell Telephone Laboratories
Nokia Bell Labs, originally named Bell Telephone Laboratories (1925–1984),
then AT&T Bell Laboratories (1984–1996)
and Bell Labs Innovations (1996–2007),
is an American industrial research and scientific development company owned by mult ...
in the 1940s. The need to identify and manipulate the properties of a system as a whole, which in complex engineering projects may greatly differ from the sum of the parts' properties, motivated various industries, especially those developing systems for the U.S. military, to apply the discipline.
When it was no longer possible to rely on design evolution to improve upon a system and the existing tools were not sufficient to meet growing demands, new methods began to be developed that addressed the complexity directly. The continuing evolution of systems engineering comprises the development and identification of new methods and modeling techniques. These methods aid in a better comprehension of the design and developmental control of engineering systems as they grow more complex. Popular tools that are often used in the systems engineering context were developed during these times, including USL,
UML
The Unified Modeling Language (UML) is a general-purpose, developmental modeling language in the field of software engineering that is intended to provide a standard way to visualize the design of a system.
The creation of UML was originally m ...
IDEF
IDEF, initially an abbreviation of ICAM Definition and renamed in 1999 as Integration Definition,IEEE Standard for Functional Modeling Language—Syntax and Semantics for IDEF0, Software Engineering Standards Committee of the IEEE Computer Soci ...
.
In 1990, a professional society for systems engineering, the ''National Council on Systems Engineering'' (NCOSE), was founded by representatives from a number of U.S. corporations and organizations. NCOSE was created to address the need for improvements in systems engineering practices and education. As a result of growing involvement from systems engineers outside of the U.S., the name of the organization was changed to the International Council on Systems Engineering (INCOSE) in 1995. Schools in several countries offer graduate programs in systems engineering, and
continuing education
Continuing education (similar to further education in the United Kingdom and Ireland) is an all-encompassing term within a broad list of post-secondary learning activities and programs. The term is used mainly in the United States and Canada.
...
options are also available for practicing engineers.
Concept
Systems engineering signifies only an approach and, more recently, a discipline in engineering. The aim of education in systems engineering is to formalize various approaches simply and in doing so, identify new methods and research opportunities similar to that which occurs in other fields of engineering. As an approach, systems engineering is holistic and interdisciplinary in flavour.
Origins and traditional scope
The traditional scope of engineering embraces the conception, design, development, production and operation of physical systems. Systems engineering, as originally conceived, falls within this scope. "Systems engineering", in this sense of the term, refers to the building of engineering concepts.
Evolution to broader scope
The use of the term "systems engineer" has evolved over time to embrace a wider, more holistic concept of "systems" and of engineering processes. This evolution of the definition has been a subject of ongoing controversy, and the term continues to apply to both the narrower and broader scope.
Traditional systems engineering was seen as a branch of engineering in the classical sense, that is, as applied only to physical systems, such as spacecraft and aircraft. More recently, systems engineering has evolved to take on a broader meaning especially when humans were seen as an essential component of a system. Peter Checkland, for example, captures the broader meaning of systems engineering by stating that 'engineering' "can be read in its general sense; you can engineer a meeting or a political agreement."
Consistent with the broader scope of systems engineering, the
Systems Engineering Body of Knowledge The Systems Engineering Body of Knowledge (SEBoK), formally known as ''Guide to the Systems Engineering Body of Knowledge,'' is a wiki-based collection of key knowledge sources and references for systems engineering. The SEBoK is a curated wiki mean ...
(SEBoK) has defined three types of systems engineering: (1) Product Systems Engineering (PSE) is the traditional systems engineering focused on the design of physical systems consisting of hardware and software. (2) Enterprise Systems Engineering (ESE) pertains to the view of enterprises, that is, organizations or combinations of organizations, as systems. (3) Service Systems Engineering (SSE) has to do with the engineering of service systems. Checkland defines a service system as a system which is conceived as serving another system. Most civil infrastructure systems are service systems.
Holistic view
Systems engineering focuses on analyzing and eliciting 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, the system lifecycle. This includes fully understanding all of the stakeholders involved. Oliver et al. claim that the systems engineering process can be decomposed into
* a ''Systems Engineering Technical Process'', and
* a ''Systems Engineering Management Process''.
Within Oliver's model, the goal of the Management Process is to organize the technical effort in the lifecycle, while the Technical Process includes ''assessing available information'', ''defining effectiveness measures'', to ''create a behavior model'', ''create a structure model'', ''perform trade-off analysis'', and ''create sequential build & test plan''.
Depending on their application, although there are several models that are used in the industry, all of them aim to identify the relation between the various stages mentioned above and incorporate feedback. Examples of such models include the
Waterfall model
The waterfall model is a breakdown of project activities into linear sequential phases, meaning they are passed down onto each other, where each phase depends on the deliverables of the previous one and corresponds to a specialization of tasks. ...
and the
VEE model
The V-model is a graphical representation of a systems development lifecycle. It is used to produce rigorous development lifecycle models and project management models. The V-model falls into three broad categories, the German ''V-Modell'', a g ...
(also called the V model).
Interdisciplinary field
System development often requires contribution from diverse technical disciplines. By providing a systems (
holistic
Holism () is the idea that various systems (e.g. physical, biological, social) should be viewed as wholes, not merely as a collection of parts. The term "holism" was coined by Jan Smuts in his 1926 book '' Holism and Evolution''."holism, n." OED On ...
) view of the development effort, systems engineering helps mold all the technical contributors into a unified team effort, forming a structured development process that proceeds from concept to production to operation and, in some cases, to termination and disposal. In an acquisition, the holistic integrative discipline combines contributions and balances tradeoffs among cost, schedule, and performance while maintaining an acceptable level of risk covering the entire life cycle of the item.
This perspective is often replicated in educational programs, in that systems engineering courses are taught by faculty from other engineering departments, which helps create an interdisciplinary environment.
Managing complexity
The need for systems engineering arose with the increase in complexity of systems and projects, in turn exponentially increasing the possibility of component friction, and therefore the unreliability of the design. When speaking in this context, complexity incorporates not only engineering systems, but also the logical human organization of data. At the same time, a system can become more complex due to an increase in size as well as with an increase in the amount of data, variables, or the number of fields that are involved in the design. The
International Space Station
The International Space Station (ISS) is the largest Modular design, modular space station currently in low Earth orbit. It is a multinational collaborative project involving five participating space agencies: NASA (United States), Roscosmos ( ...
is an example of such a system.
The development of smarter control
algorithms
In mathematics and computer science, an algorithm () is a finite sequence of rigorous instructions, typically used to solve a class of specific problems or to perform a computation. Algorithms are used as specifications for performing ...
, microprocessor design, and analysis of environmental systems also come within the purview of systems engineering. Systems engineering encourages the use of tools and methods to better comprehend and manage complexity in systems. Some examples of these tools can be seen here:
* ''
System architecture A system architecture is the conceptual model that defines the structure, behavior, and more views of a system. An architecture description is a formal description and representation of a system, organized in a way that supports reasoning about the ...
'',
* ''
System model
Systems modeling or system modeling is the interdisciplinary study of the use of models to conceptualize and construct systems in business and IT development.Modeling
A model is an informative representation of an object, person or system. The term originally denoted the plans of a building in late 16th-century English, and derived via French and Italian ultimately from Latin ''modulus'', a measure.
Models c ...
, and
Simulation
A simulation is the imitation of the operation of a real-world process or system over time. Simulations require the use of Conceptual model, models; the model represents the key characteristics or behaviors of the selected system or proc ...
'',
* ''
Optimization
Mathematical optimization (alternatively spelled ''optimisation'') or mathematical programming is the selection of a best element, with regard to some criterion, from some set of available alternatives. It is generally divided into two subfi ...
'',
* ''
System dynamics
System dynamics (SD) is an approach to understanding the nonlinear behaviour of complex systems over time using stocks, flows, internal feedback loops, table functions and time delays.
Overview
System dynamics is a methodology and mathematica ...
'',
* ''
Systems analysis
Systems analysis is "the process of studying a procedure or business to identify its goal and purposes and create systems and procedures that will efficiently achieve them". Another view sees system analysis as a problem-solving technique that ...
'',
* ''
Statistical analysis
Statistical inference is the process of using data analysis to infer properties of an underlying distribution of probability.Upton, G., Cook, I. (2008) ''Oxford Dictionary of Statistics'', OUP. . Inferential statistical analysis infers propertie ...
'',
* ''
Reliability analysis
Reliability, reliable, or unreliable may refer to:
Science, technology, and mathematics Computing
* Data reliability (disambiguation), a property of some disk arrays in computer storage
* High availability
* Reliability (computer networking), a ...
'', and
* ''
Decision making
In psychology, decision-making (also spelled decision making and decisionmaking) is regarded as the cognitive process resulting in the selection of a belief or a course of action among several possible alternative options. It could be either ra ...
''
Taking an
interdisciplinary
Interdisciplinarity or interdisciplinary studies involves the combination of multiple academic disciplines into one activity (e.g., a research project). It draws knowledge from several other fields like sociology, anthropology, psychology, ec ...
approach to engineering systems is inherently complex since the
behavior
Behavior (American English) or behaviour (British English) is the range of actions and mannerisms made by individuals, organisms, systems or artificial entities in some environment. These systems can include other systems or organisms as we ...
of and interaction among system components is not always immediately
well defined
In mathematics, a well-defined expression or unambiguous expression is an expression whose definition assigns it a unique interpretation or value. Otherwise, the expression is said to be ''not well defined'', ill defined or ''ambiguous''. A func ...
or understood. Defining and characterizing such
system
A system is a group of interacting or interrelated elements that act according to a set of rules to form a unified whole. A system, surrounded and influenced by its environment, is described by its boundaries, structure and purpose and express ...
s and subsystems and the interactions among them is one of the goals of systems engineering. In doing so, the gap that exists between informal requirements from users, operators, marketing organizations, and technical specifications is successfully bridged.
Scope
One way to understand the motivation behind systems engineering is to see it as a method, or practice, to identify and improve common rules that exist within a wide variety of systems. Keeping this in mind, the principles of systems engineering – holism, emergent behavior, boundary, et al. – can be applied to any system, complex or otherwise, provided
systems thinking
Systems thinking is a way of making sense of the complexity of the world by looking at it in terms of wholes and relationships rather than by splitting it down into its parts. It has been used as a way of exploring and developing effective actio ...
is employed at all levels. Besides defense and aerospace, many information and technology based companies, software development firms, and industries in the field of electronics & communications require systems engineers as part of their team.
An analysis by the INCOSE Systems Engineering center of excellence (SECOE) indicates that optimal effort spent on systems engineering is about 15–20% of the total project effort. At the same time, studies have shown that systems engineering essentially leads to reduction in costs among other benefits. However, no quantitative survey at a larger scale encompassing a wide variety of industries has been conducted until recently. Such studies are underway to determine the effectiveness and quantify the benefits of systems engineering.
Systems engineering encourages the use of
modeling and simulation
Modeling and simulation (M&S) is the use of models (e.g., physical, mathematical, or logical representation of a system, entity, phenomenon, or process) as a basis for simulations to develop data utilized for managerial or technical decision makin ...
to validate assumptions or theories on systems and the interactions within them.
Use of methods that allow early detection of possible failures, in safety engineering, are integrated into the design process. At the same time, decisions made at the beginning of a project whose consequences are not clearly understood can have enormous implications later in the life of a system, and it is the task of the modern systems engineer to explore these issues and make critical decisions. No method guarantees today's decisions will still be valid when a system goes into service years or decades after first conceived. However, there are techniques that support the process of systems engineering. Examples include soft systems methodology,
Jay Wright Forrester
Jay Wright Forrester (July 14, 1918 – November 16, 2016) was a pioneering American computer engineer and systems scientist. He is credited with being one of the inventors of magnetic core memory, the predominant form of random-access compu ...
's
System dynamics
System dynamics (SD) is an approach to understanding the nonlinear behaviour of complex systems over time using stocks, flows, internal feedback loops, table functions and time delays.
Overview
System dynamics is a methodology and mathematica ...
method, and the
Unified Modeling Language
The Unified Modeling Language (UML) is a general-purpose, developmental modeling language in the field of software engineering that is intended to provide a standard way to visualize the design of a system.
The creation of UML was originally m ...
(UML)—all currently being explored, evaluated, and developed to support the engineering decision process.
Education
Education in systems engineering is often seen as an extension to the regular engineering courses, reflecting the industry attitude that engineering students need a foundational background in one of the traditional engineering disciplines (e.g.,
aerospace engineering
Aerospace engineering is the primary field of engineering concerned with the development of aircraft and spacecraft. It has two major and overlapping branches: aeronautical engineering and astronautical engineering. Avionics engineering is s ...
,
civil engineering
Civil engineering is a professional engineering discipline that deals with the design, construction, and maintenance of the physical and naturally built environment, including public works such as roads, bridges, canals, dams, airports, sewa ...
,
electrical engineering
Electrical engineering is an engineering discipline concerned with the study, design, and application of equipment, devices, and systems which use electricity, electronics, and electromagnetism. It emerged as an identifiable occupation in the l ...
,
mechanical engineering
Mechanical engineering is the study of physical machines that may involve force and movement. It is an engineering branch that combines engineering physics and mathematics principles with materials science, to design, analyze, manufacture, ...
,
manufacturing engineering
Manufacturing engineering or production engineering is a branch of professional engineering that shares many common concepts and ideas with other fields of engineering such as mechanical, chemical, electrical, and industrial engineering.
Manufa ...
,
industrial engineering
Industrial engineering is an engineering profession that is concerned with the optimization of complex processes, systems, or organizations by developing, improving and implementing integrated systems of people, money, knowledge, information an ...
,
chemical engineering
Chemical engineering is an engineering field which deals with the study of operation and design of chemical plants as well as methods of improving production. Chemical engineers develop economical commercial processes to convert raw materials in ...
)—plus practical, real-world experience to be effective as systems engineers. Undergraduate university programs explicitly in systems engineering are growing in number but remain uncommon, the degrees including such material most often presented as a BS in Industrial Engineering. Typically programs (either by themselves or in combination with interdisciplinary study) are offered beginning at the graduate level in both academic and professional tracks, resulting in the grant of either a MS/
MEng
Meng may refer to:
* Meng (surname) (孟), a Chinese surname
* Master of Engineering (MEng or M.Eng.), an academic or professional master's degree in the field of engineering
* , "M with hook", letter used in the International Phonetic Alphabet
* ...
EngD
The Doctor of Engineering, or Engineering Doctorate, (abbreviated DEng, EngD, or Dr-Ing) is a degree awarded on the basis of advanced study and a practical project in the engineering and applied science for solving problems in the industry. In the ...
degree.
INCOSE
The International Council on Systems Engineering (INCOSE; pronounced in-co-see) is a not-for-profit membership organization and professional society in the field of systems engineering. INCOSE has about 17000 members including individual members, ...
, in collaboration with the Systems Engineering Research Center at
Stevens Institute of Technology
Stevens Institute of Technology is a private research university in Hoboken, New Jersey. Founded in 1870, it is one of the oldest technological universities in the United States and was the first college in America solely dedicated to mechanical ...
maintains a regularly updated directory of worldwide academic programs at suitably accredited institutions. As of 2017, it lists over 140 universities in North America offering more than 400 undergraduate and graduate programs in systems engineering. Widespread institutional acknowledgment of the field as a distinct subdiscipline is quite recent; the 2009 edition of the same publication reported the number of such schools and programs at only 80 and 165, respectively.
Education in systems engineering can be taken as ''Systems-centric'' or ''Domain-centric'':
* ''Systems-centric'' programs treat systems engineering as a separate discipline and most of the courses are taught focusing on systems engineering principles and practice.
* ''Domain-centric'' programs offer systems engineering as an option that can be exercised with another major field in engineering.
Both of these patterns strive to educate the systems engineer who is able to oversee interdisciplinary projects with the depth required of a core-engineer.
Systems engineering topics
Systems engineering tools are
strategies
Strategy (from Greek στρατηγία ''stratēgia'', "art of troop leader; office of general, command, generalship") is a general plan to achieve one or more long-term or overall goals under conditions of uncertainty. In the sense of the " ar ...
, procedures, and techniques that aid in performing systems engineering on a project or
product
Product may refer to:
Business
* Product (business), an item that serves as a solution to a specific consumer problem.
* Product (project management), a deliverable or set of deliverables that contribute to a business solution
Mathematics
* Produ ...
. The purpose of these tools vary from database management, graphical browsing, simulation, and reasoning, to document production, neutral import/export and more.
System
There are many definitions of what a
system
A system is a group of interacting or interrelated elements that act according to a set of rules to form a unified whole. A system, surrounded and influenced by its environment, is described by its boundaries, structure and purpose and express ...
is in the field of systems engineering. Below are a few authoritative definitions:
*
ANSI
The American National Standards Institute (ANSI ) is a private non-profit organization that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States. The organi ...
/
EIA Eia or EIA may refer to:
Medicine
* Enzyme immunoassay
* Equine infectious anemia
* Exercise-induced anaphylaxis
* Exercise-induced asthma
* External iliac artery
Transport
* Edmonton International Airport, in Alberta, Canada
* Erbil Internation ...
-632-1999: "An aggregation of end products and enabling products to achieve a given purpose."
* DAU Systems Engineering Fundamentals: "an integrated composite of people, products, and processes that provide a capability to satisfy a stated need or objective."
*
IEEE
The Institute of Electrical and Electronics Engineers (IEEE) is a 501(c)(3) professional association for electronic engineering and electrical engineering (and associated disciplines) with its corporate office in New York City and its operat ...
Std 1220-1998: "A set or arrangement of elements and processes that are related and whose behavior satisfies customer/operational needs and provides for life cycle sustainment of the products."
*
INCOSE
The International Council on Systems Engineering (INCOSE; pronounced in-co-see) is a not-for-profit membership organization and professional society in the field of systems engineering. INCOSE has about 17000 members including individual members, ...
Systems Engineering Handbook: "homogeneous entity that exhibits predefined behavior in the real world and is composed of heterogeneous parts that do not individually exhibit that behavior and an integrated configuration of components and/or subsystems."
*
INCOSE
The International Council on Systems Engineering (INCOSE; pronounced in-co-see) is a not-for-profit membership organization and professional society in the field of systems engineering. INCOSE has about 17000 members including individual members, ...
: "A system is a construct or collection of different elements that together produce results not obtainable by the elements alone. The elements, or parts, can include people, hardware, software, facilities, policies, and documents; that is, all things required to produce systems-level results. The results include system level qualities, properties, characteristics, functions, behavior and performance. The value added by the system as a whole, beyond that contributed independently by the parts, is primarily created by the relationship among the parts; that is, how they are interconnected."
*
ISO/IEC
ISO/IEC JTC 1, entitled "Information technology", is a joint technical committee (JTC) of the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC). Its purpose is to develop, maintain and p ...
15288:2008: "A combination of interacting elements organized to achieve one or more stated purposes."
*
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the US federal government responsible for the civil List of government space agencies, space program ...
Systems Engineering Handbook: "(1) The combination of elements that function together to produce the capability to meet a need. The elements include all hardware, software, equipment, facilities, personnel, processes, and procedures needed for this purpose. (2) The end product (which performs operational functions) and enabling products (which provide life-cycle support services to the operational end products) that make up a system."
Systems engineering processes
Systems engineering processes encompass all creative, manual and technical activities necessary to define the product and which need to be carried out to convert a system definition to a sufficiently detailed system design specification for product manufacture and deployment. Design and development of a system can be divided into four stages, each with different definitions:
* task definition (informative definition),
* conceptual stage (cardinal definition),
* design stage (formative definition), and
* implementation stage (manufacturing definition).
Depending on their application, tools are used for various stages of the systems engineering process:
:
Using models
Model
A model is an informative representation of an object, person or system. The term originally denoted the plans of a building in late 16th-century English, and derived via French and Italian ultimately from Latin ''modulus'', a measure.
Models c ...
s play important and diverse roles in systems engineering. A model can be defined in several
ways, including:NASA (1995). "System Analysis and Modeling Issues". In: ' NASA Systems Engineering Handbook '' June 1995. p.85.
* An abstraction of reality designed to answer specific questions about the real world
* An imitation, analogue, or representation of a real world process or structure; or
* A conceptual, mathematical, or physical tool to assist a decision maker.
Together, these definitions are broad enough to encompass physical engineering models used in the verification of a system design, as well as schematic models like a
functional flow block diagram
A functional flow block diagram (FFBD) is a multi-tier, time-sequenced, step-by-step flow diagram of a system’s functional flow. The term "functional" in this context is different from its use in functional programming or in mathematics, where p ...
and mathematical (i.e., quantitative) models used in the trade study process. This section focuses on the last.
The main reason for using mathematical models and
diagrams
A diagram is a symbolic representation of information using visualization techniques. Diagrams have been used since prehistoric times on walls of caves, but became more prevalent during the Enlightenment. Sometimes, the technique uses a three- ...
in trade studies is to provide estimates of system effectiveness, performance or technical attributes, and cost from a set of known or estimable quantities. Typically, a collection of separate models is needed to provide all of these outcome variables. The heart of any mathematical model is a set of meaningful quantitative relationships among its inputs and outputs. These relationships can be as simple as adding up constituent quantities to obtain a total, or as complex as a set of differential equations describing the trajectory of a spacecraft in a gravitational field. Ideally, the relationships express causality, not just correlation. Furthermore, key to successful systems engineering activities are also the methods with which these models are efficiently and effectively managed and used to simulate the systems. However, diverse domains often present recurring problems of modeling and simulation for systems engineering, and new advancements are aiming to cross-fertilize methods among distinct scientific and engineering communities, under the title of 'Modeling & Simulation-based Systems Engineering'.
Modeling formalisms and graphical representations
Initially, when the primary purpose of a systems engineer is to comprehend a complex problem, graphic representations of a system are used to communicate a system's functional and data requirements. Common graphical representations include:
*
Functional flow block diagram
A functional flow block diagram (FFBD) is a multi-tier, time-sequenced, step-by-step flow diagram of a system’s functional flow. The term "functional" in this context is different from its use in functional programming or in mathematics, where p ...
(FFBD)
*
Model-based design
Model-based design (MBD) is a mathematical and visual method of addressing problems associated with designing complex control, signal processing and communication systems. It is used in many motion control, industrial equipment, aerospace, and aut ...
*
Data flow diagram
A data-flow diagram is a way of representing a flow of data through a process or a system (usually an information system). The DFD also provides information about the outputs and inputs of each entity and the process itself. A data-flow diagram h ...
(DFD)
*
N2 chart
The ''N'' 2 chart, also referred to as ''N'' 2 diagram, ''N''-squared diagram or ''N''-squared chart, is a diagram in the shape of a matrix, representing functional or physical interfaces between system elements. It is used to systematica ...
Use case diagram
A use case diagram is a graphical depiction of a user's possible interactions with a system. A use case diagram shows various use cases and different types of users the system has and will often be accompanied by other types of diagrams as well. Th ...
*
Sequence diagram
A sequence diagram or system sequence diagram (SSD) shows process interactions arranged in time sequence in the field of software engineering. It depicts the processes involved and the sequence of messages exchanged between the processes needed ...
*
Block diagram
A block diagram is a diagram of a system in which the principal parts or functions are represented by blocks connected by lines that show the relationships of the blocks.
*
Signal-flow graph
A signal-flow graph or signal-flowgraph (SFG), invented by Claude Shannon, but often called a Mason graph after Samuel Jefferson Mason who coined the term, is a specialized flow graph, a directed graph in which nodes represent system variables, ...
Enterprise architecture framework
An enterprise architecture framework (EA framework) defines how to create and use an enterprise architecture. An architecture framework provides principles and practices for creating and using the architecture description of a system. It struct ...
s
A graphical representation relates the various subsystems or parts of a system through functions, data, or interfaces. Any or each of the above methods are used in an industry based on its requirements. For instance, the N2 chart may be used where interfaces between systems is important. Part of the design phase is to create structural and behavioral models of the system.
Once the requirements are understood, it is now the responsibility of a systems engineer to refine them, and to determine, along with other engineers, the best technology for a job. At this point starting with a trade study, systems engineering encourages the use of weighted choices to determine the best option. A
decision matrix
A decision matrix is a list of values in rows and columns that allows an analyst to systematically identify, analyze, and rate the performance of relationships between sets of values and information. Elements of a decision matrix show decisions bas ...
, or Pugh method, is one way ( QFD is another) to make this choice while considering all criteria that are important. The trade study in turn informs the design, which again affects graphic representations of the system (without changing the requirements). In an SE process, this stage represents the iterative step that is carried out until a feasible solution is found. A decision matrix is often populated using techniques such as statistical analysis, reliability analysis, system dynamics (feedback control), and optimization methods.
Other tools
Systems Modeling Language
The Systems Modeling Language (SysML) is a general-purpose modeling language for systems engineering applications. It supports the specification, analysis, design, verification and validation of a broad range of systems and systems-of-systems.
S ...
(SysML), a modeling language used for systems engineering applications, supports the specification, analysis, design, verification and validation of a broad range of complex systems.
Lifecycle Modeling Language The Lifecycle Modeling Language (LML) is an open-standard modeling language designed for systems engineering. It supports the full lifecycle: conceptual, utilization, support and retirement stages. Along with the integration of all lifecycle discipl ...
(LML), is an open-standard modeling language designed for systems engineering that supports the full lifecycle: conceptual, utilization, support and retirement stages.
Related fields and sub-fields
Many related fields may be considered tightly coupled to systems engineering. The following areas have contributed to the development of systems engineering as a distinct entity:
;Cognitive systems engineering
:Cognitive systems engineering (CSE) is a specific approach to the description and analysis of human-machine systems or
sociotechnical systems
Sociotechnical systems (STS) in organizational development is an approach to complex organizational work design that recognizes the interaction between people and technology in workplaces. The term also refer to coherent systems of human relatio ...
. The three main themes of CSE are how humans cope with complexity, how work is accomplished by the use of artifacts, and how human-machine systems and socio-technical systems can be described as joint cognitive systems. CSE has since its beginning become a recognized scientific discipline, sometimes also referred to as
cognitive engineering
Cognitive engineering is a method of study using cognitive psychology to design and develop engineering systems to support the cognitive processes of users.
History
It was an engineering method used in the 1970s at Bell Labs, focused on how peopl ...
. The concept of a Joint Cognitive System (JCS) has in particular become widely used as a way of understanding how complex socio-technical systems can be described with varying degrees of resolution. The more than 20 years of experience with CSE has been described extensively.
;Configuration management
:Like systems engineering, configuration management as practiced in the defense and aerospace industry is a broad systems-level practice. The field parallels the taskings of systems engineering; where systems engineering deals with requirements development, allocation to development items and verification, configuration management deals with requirements capture, traceability to the development item, and audit of development item to ensure that it has achieved the desired functionality that systems engineering and/or Test and Verification Engineering have proven out through objective testing.
;Control engineering
:
Control engineering
Control engineering or control systems engineering is an engineering discipline that deals with control systems, applying control theory to design equipment and systems with desired behaviors in control environments. The discipline of controls o ...
and its design and implementation of
control systems
A control system manages, commands, directs, or regulates the behavior of other devices or systems using control loops. It can range from a single home heating controller using a thermostat controlling a domestic boiler to large industrial c ...
, used extensively in nearly every industry, is a large sub-field of systems engineering. The cruise control on an automobile and the guidance system for a ballistic missile are two examples. Control systems theory is an active field of applied mathematics involving the investigation of solution spaces and the development of new methods for the analysis of the control process.
;Industrial engineering
:
Industrial engineering
Industrial engineering is an engineering profession that is concerned with the optimization of complex processes, systems, or organizations by developing, improving and implementing integrated systems of people, money, knowledge, information a ...
is a branch of
engineering
Engineering is the use of scientific principles to design and build machines, structures, and other items, including bridges, tunnels, roads, vehicles, and buildings. The discipline of engineering encompasses a broad range of more speciali ...
that concerns the development, improvement, implementation and evaluation of integrated systems of people, money, knowledge, information, equipment, energy, material and process. Industrial engineering draws upon the principles and methods of engineering analysis and synthesis, as well as mathematical, physical and social sciences together with the principles and methods of engineering analysis and design to specify, predict, and evaluate results obtained from such systems.
;Production Systems Engineering
:Production Systems Engineering (PSE) is an emerging branch of Engineering intended to uncover fundamental principles of production systems and utilize them for analysis, continuous improvement, and design.
;Interface design
:
Interface design
User interface (UI) design or user interface engineering is the design of user interfaces for machines and software, such as computers, home appliances, mobile devices, and other electronic devices, with the focus on maximizing usability and t ...
and its specification are concerned with assuring that the pieces of a system connect and inter-operate with other parts of the system and with external systems as necessary. Interface design also includes assuring that system interfaces be able to accept new features, including mechanical, electrical and logical interfaces, including reserved wires, plug-space, command codes and bits in communication protocols. This is known as extensibility. Human-Computer Interaction (HCI) or Human-Machine Interface (HMI) is another aspect of interface design, and is a critical aspect of modern systems engineering. Systems engineering principles are applied in the design of
communication protocols
A communication protocol is a system of rules that allows two or more entities of a communications system to transmit information via any kind of variation of a physical quantity. The protocol defines the rules, syntax, semantics and synchron ...
for
local area networks
A local area network (LAN) is a computer network that interconnects computers within a limited area such as a residence, school, laboratory, university campus or office building. By contrast, a wide area network (WAN) not only covers a larger ...
and
wide area networks
A wide area network (WAN) is a telecommunications network that extends over a large geographic area. Wide area networks are often established with leased telecommunication circuits.
Businesses, as well as schools and government entities, us ...
.
;Mechatronic engineering
:
Mechatronic engineering
Mechatronics engineering also called mechatronics, is an interdisciplinary branch of engineering that focuses on the integration of mechanical, electrical and electronic engineering systems, and also includes a combination of robotics, electronics ...
, like systems engineering, is a multidisciplinary field of engineering that uses dynamical systems modeling to express tangible constructs. In that regard it is almost indistinguishable from Systems Engineering, but what sets it apart is the focus on smaller details rather than larger generalizations and relationships. As such, both fields are distinguished by the scope of their projects rather than the methodology of their practice.
;Operations research
:
Operations research
Operations research ( en-GB, operational research) (U.S. Air Force Specialty Code: Operations Analysis), often shortened to the initialism OR, is a discipline that deals with the development and application of analytical methods to improve decis ...
supports systems engineering. The tools of operations research are used in systems analysis, decision making, and trade studies. Several schools teach SE courses within the
operations research
Operations research ( en-GB, operational research) (U.S. Air Force Specialty Code: Operations Analysis), often shortened to the initialism OR, is a discipline that deals with the development and application of analytical methods to improve decis ...
or
industrial engineering
Industrial engineering is an engineering profession that is concerned with the optimization of complex processes, systems, or organizations by developing, improving and implementing integrated systems of people, money, knowledge, information an ...
department, highlighting the role systems engineering plays in complex projects.
Operations research
Operations research ( en-GB, operational research) (U.S. Air Force Specialty Code: Operations Analysis), often shortened to the initialism OR, is a discipline that deals with the development and application of analytical methods to improve decis ...
, briefly, is concerned with the optimization of a process under multiple constraints.
;Performance engineering
:
Performance engineering
Performance engineering encompasses the techniques applied during a systems development life cycle to ensure the non-functional requirements for performance (such as throughput, latency, or memory usage) will be met. It may be alternatively refe ...
is the discipline of ensuring a system meets customer expectations for performance throughout its life. Performance is usually defined as the speed with which a certain operation is executed, or the capability of executing a number of such operations in a unit of time. Performance may be degraded when operations queued to execute is throttled by limited system capacity. For example, the performance of a
packet-switched network
In telecommunications, packet switching is a method of grouping data into '' packets'' that are transmitted over a digital network. Packets are made of a header and a payload. Data in the header is used by networking hardware to direct the pack ...
is characterized by the end-to-end packet transit delay, or the number of packets switched in an hour. The design of high-performance systems uses analytical or simulation modeling, whereas the delivery of high-performance implementation involves thorough performance testing. Performance engineering relies heavily on statistics,
queueing theory
Queueing theory is the mathematical study of waiting lines, or queues. A queueing model is constructed so that queue lengths and waiting time can be predicted. Queueing theory is generally considered a branch of operations research because the ...
and
probability theory
Probability theory is the branch of mathematics concerned with probability. Although there are several different probability interpretations, probability theory treats the concept in a rigorous mathematical manner by expressing it through a set ...
for its tools and processes.
;Program management and project management
:
Program management
Program management, is the process of managing several related projects, often with the intention of improving an organization's performance. It is distinct from ''project'' management.
In practice and in its aims, program management is oft ...
(or programme management) has many similarities with systems engineering, but has broader-based origins than the engineering ones of systems engineering.
Project management
Project management is the process of leading the work of a team to achieve all project goals within the given constraints. This information is usually described in project documentation, created at the beginning of the development process. T ...
is also closely related to both program management and systems engineering.
;Proposal engineering
:Proposal engineering is the application of scientific and mathematical principles to design, construct, and operate a cost-effective proposal development system. Basically, proposal engineering uses the "
systems engineering process
Systems engineering is an interdisciplinary field of engineering and engineering management that focuses on how to design, integrate, and manage complex systems over their life cycles. At its core, systems engineering utilizes systems thinking ...
" to create a cost-effective proposal and increase the odds of a successful proposal.
;Reliability engineering
: Reliability engineering is the discipline of ensuring a system meets customer expectations for reliability throughout its life; i.e., it does not fail more frequently than expected. Next to prediction of failure, it is just as much about prevention of failure. Reliability engineering applies to all aspects of the system. It is closely associated with
maintainability
In engineering, maintainability is the ease with which a product can be maintained to:
* correct defects or their cause,
* Repair or replace faulty or worn-out components without having to replace still working parts,
* prevent unexpected working ...
,
availability
In reliability engineering, the term availability has the following meanings:
* The degree to which a system, subsystem or equipment is in a specified operable and committable state at the start of a mission, when the mission is called for at ...
(
dependability
In systems engineering, dependability is a measure of a system's availability, reliability, maintainability, and in some cases, other characteristics such as durability, safety and security. In real-time computing, dependability is the ability to ...
risk
In simple terms, risk is the possibility of something bad happening. Risk involves uncertainty about the effects/implications of an activity with respect to something that humans value (such as health, well-being, wealth, property or the environm ...
is one of the interdisciplinary parts of Systems Engineering. In development, acquisition, or operational activities, the inclusion of risk in tradeoff with cost, schedule, and performance features, involves the iterative complex configuration management of traceability and evaluation to the scheduling and requirements management across domains and for the system lifecycle that requires the interdisciplinary technical approach of systems engineering. Systems Engineering has Risk Management define, tailor, implement, and monitor a structured process for risk management which is integrated to the overall effort.
;Safety engineering
:The techniques of safety engineering may be applied by non-specialist engineers in designing complex systems to minimize the probability of safety-critical failures. The "System Safety Engineering" function helps to identify "safety hazards" in emerging designs, and may assist with techniques to "mitigate" the effects of (potentially) hazardous conditions that cannot be designed out of systems.
;Scheduling
:
Scheduling
A schedule or a timetable, as a basic time-management tool, consists of a list of times at which possible tasks, events, or actions are intended to take place, or of a sequence of events in the chronological order in which such things are ...
is one of the systems engineering support tools as a practice and item in assessing interdisciplinary concerns under configuration management. In particular the direct relationship of resources, performance features, and risk to duration of a task or the dependency links among tasks and impacts across the system lifecycle are systems engineering concerns.
;Security engineering
: Security engineering can be viewed as an
interdisciplinary
Interdisciplinarity or interdisciplinary studies involves the combination of multiple academic disciplines into one activity (e.g., a research project). It draws knowledge from several other fields like sociology, anthropology, psychology, ec ...
field that integrates the community of practice for control systems design, reliability, safety and systems engineering. It may involve such sub-specialties as
authentication
Authentication (from ''authentikos'', "real, genuine", from αὐθέντης ''authentes'', "author") is the act of proving an assertion, such as the identity of a computer system user. In contrast with identification, the act of indicatin ...
of system users, system targets and others: people, objects and processes.
;Software engineering
:From its beginnings,
software engineering
Software engineering is a systematic engineering approach to software development.
A software engineer is a person who applies the principles of software engineering to design, develop, maintain, test, and evaluate computer software. The term '' ...
has helped shape modern systems engineering practice. The techniques used in the handling of the complexities of large software-intensive systems have had a major effect on the shaping and reshaping of the tools, methods and processes of Systems Engineering.
See also
*
Arcadia (engineering)
ARCADIA (Architecture Analysis & Design Integrated Approach) is a Systems engineering, system and Software engineering, software architecture engineering method based on architecture-centric and model-driven engineering activities.
History
In ...
*
Control engineering
Control engineering or control systems engineering is an engineering discipline that deals with control systems, applying control theory to design equipment and systems with desired behaviors in control environments. The discipline of controls o ...
*
Design review (U.S. government)
In the United States military integrated acquisition lifecycle the Technical section has multiple acquisition "Technical Reviews". Technical reviews and audits assist the acquisition and the number and types are tailored to the acquisition. Over ...
*
Engineering management
Engineering management is the application of the practice of management to the practice of engineering.
Engineering management is a career that brings together the technological problem-solving ability of engineering and the organizational, admini ...
*
Engineering information management Engineering information management (EIM) is the business function within product development and specifically systems engineering that allows engineers to collaborate on a single source of truth of engineering data.
Contrary to product data managem ...
Industrial engineering
Industrial engineering is an engineering profession that is concerned with the optimization of complex processes, systems, or organizations by developing, improving and implementing integrated systems of people, money, knowledge, information a ...
List of production topics
The following outline is provided as an overview of and topical guide to production:
Production – act of creating 'use' value or 'utility' that can satisfy a want or need. The act may or may not include factors of production other than l ...
*
List of requirements engineering tools
Requirements engineering tools are usually software products to ease the RE processes and allow for more systematic and formalized handling of requirements, change management and traceability.
The PMI guide ''Requirements Management: A Practical ...
*
List of systems engineers
This is a list of notable systems engineers, people who were trained in or practice systems engineering, and made notable contributions to this field in theory or practice.
__NOTOC__
A
* James S. Albus (1935–2011), American engineer, founder ...
*
List of types of systems engineering This list of types of systems engineering gives an overview of the types of systems engineering. The #References, reference section gives an overview of major publications in each field and the universities that offer these programs. Universities ca ...
*
Management cybernetics
Management cybernetics is concerned with the application of cybernetics to management and organizations. "Management cybernetics" was first introduced by Stafford Beer in the late 1950s and introduces the various mechanisms of self-regulation appli ...
*
Model-based systems engineering Model-based systems engineering (MBSE), according to the International Council on Systems Engineering (INCOSE), is the ''formalized application of modeling to support system requirements, design, analysis, verification and validation activities beg ...
Structured systems analysis and design method
Structuring, also known as smurfing in banking jargon, is the practice of executing financial transactions such as making bank deposits in a specific pattern, calculated to avoid triggering financial institutions to file reports required by law ...
*
System of systems engineering System of systems engineering (SoSE) is a set of developing processes, tools, and methods for designing, re-designing and deploying solutions to system-of-systems challenges.
Overview
System of Systems Engineering (SoSE) methodology is heavily u ...
Systems architecture A system architecture is the conceptual model that defines the structure, behavior, and more views of a system. An architecture description is a formal description and representation of a system, organized in a way that supports reasoning about the ...
*
Systems development life cycle
In systems engineering, information systems and software engineering, the systems development life cycle (SDLC), also referred to as the application development life cycle, is a process for planning, creating, testing, and deploying an informa ...
value-stream mapping
Value-stream mapping, also known as "material- and information-flow mapping", is a lean-management method for analyzing the current state and designing a future state for the series of events that take a product or service from the beginning of ...
)
*
System information modelling System information modelling (SIM) is the process of modelling complex connected systems. System information models are digital representations of connected systems, such as electrical instrumentation and control, power, and communication systems. ...
References
Further reading
* Blockley, D. Godfrey, P. Doing it Differently: Systems for Rethinking Infrastructure, Second Edition ', ICE Publications, London, 2017.
* Buede, D.M., Miller, W.D. ', John Wiley and Sons, 2016.
* Chestnut, H., ''Systems Engineering Methods''. Wiley, 1967.
* Gianni, D. et al. (eds.), ''Modeling and Simulation-Based Systems Engineering Handbook'', CRC Press, 201 at CRC * Goode, H.H., Robert E. Machol ''System Engineering: An Introduction to the Design of Large-scale Systems'', McGraw-Hill, 1957.
* Hitchins, D. (1997 ''World Class Systems Engineering'' at hitchins.net.
* Lienig, J., Bruemmer, H. ''Fundamentals of Electronic Systems Design'' Springer, 2017 .
* Malakooti, B. (2013). Operations and Production Systems with Multiple Objectives. John Wiley & Sons.
* MITRE The MITRE Systems Engineering Guidepdf
* NASA (2007) Systems Engineering Handbook ', NASA/SP-2007-6105 Rev1, December 2007.
* NASA (2013) NASA Systems Engineering Processes and Requirements ' NPR 7123.1B, April 2013 NASA Procedural Requirements
* Oliver, D.W., et al. ''Engineering Complex Systems with Models and Objects. McGraw-Hill'', 1997.
* Parnell, G.S., Driscoll, P.J., Henderson, D.L. (eds.), ''Decision Making in Systems Engineering and Management'', 2nd. ed., Hoboken, NJ: Wiley, 2011. This is a textbook for undergraduate students of engineering.
* Ramo, S., St.Clair, R.K. ''The Systems Approach: Fresh Solutions to Complex Problems Through Combining Science and Practical Common Sense'', Anaheim, CA: KNI, Inc, 1998.
* Sage, A.P., ''Systems Engineering''. Wiley IEEE, 1992. .
* Sage, A.P., Olson, S.R., ''Modeling and Simulation in Systems Engineering'', 2001.
* SEBOK.org Systems Engineering Body of Knowledge (SEBoK) * Shermon, D ''Systems Cost Engineering''
Gower publishing
Ashgate Publishing was an academic book and journal publisher based in Farnham ( Surrey, United Kingdom). It was established in 1967 and specialised in the social sciences, arts, humanities and professional practice. It had an American office i ...