Software development methodology - AbsoluteAstronomy.com

A software development methodology or system development methodology in software engineering

Software engineering

Software Engineering is the application of a systematic, disciplined, quantifiable approach to the development, operation, and maintenance of software, and the study of these approaches; that is, the application of engineering to software...

is a framework that is used to structure, plan, and control the process of developing

Software development process

A software development process, also known as a software development life cycle , is a structure imposed on the development of a software product. Similar terms include software life cycle and software process. It is often considered a subset of systems development life cycle...

an information system

Information system

An information system - or application landscape - is any combination of information technology and people's activities that support operations, management, and decision making. In a very broad sense, the term information system is frequently used to refer to the interaction between people,...

History

The software development methodology (also known as SDM) framework didn't emerge until the 1960s. According to Elliott (2004) the systems development life cycle

Systems Development Life Cycle

The systems development life cycle , or software development life cycle in systems engineering, information systems and software engineering, is a process of creating or altering information systems, and the models and methodologies that people use to develop these systems.In software engineering...

(SDLC) can be considered to be the oldest formalized methodology framework for building information system

Information system

s. The main idea of the SDLC has been "to pursue the development of information systems in a very deliberate, structured and methodical way, requiring each stage of the life cycle

Software development process

from inception of the idea to delivery of the final system, to be carried out rigidly and sequentially". within the context of the framework being applied. The main target of this methodology framework in the 1960s was "to develop large scale functional business systems in an age of large scale business conglomerates. Information systems activities revolved around heavy data processing

Data processing

Computer data processing is any process that a computer program does to enter data and summarise, analyse or otherwise convert data into usable information. The process may be automated and run on a computer. It involves recording, analysing, sorting, summarising, calculating, disseminating and...

and number crunching routines".

As a noun

As a noun, a software development methodology is a framework that is used to structure, plan, and control the process of developing

Software development process

an information system

Information system

- this includes the pre-definition of specific deliverables and artifacts that are created and completed by a project team to develop or maintain an application.
A wide variety of such frameworks have evolved over the years, each with its own recognized strengths and weaknesses. One software development methodology framework is not necessarily suitable for use by all projects. Each of the available methodology frameworks are best suited to specific kinds of projects, based on various technical, organizational, project and team considerations.

These software development frameworks are often bound to some kind of organization, which further develops, supports the use, and promotes the methodology framework. The methodology framework is often defined in some kind of formal documentation. Specific software development methodology frameworks (noun) include

Rational Unified Process
Rational Unified Process
The Rational Unified Process is an iterative software development process framework created by the Rational Software Corporation, a division of IBM since 2003...

(RUP, IBM) since 1998.
Agile Unified Process
Agile Unified Process
Agile Unified Process is a simplified version of the IBM Rational Unified Process developed by Scott Ambler. It describes a simple, easy to understand approach to developing business application software using agile techniques and concepts yet still remaining true to the RUP...

(AUP) since 2005 by Scott Ambler
Scott Ambler
Scott W. Ambler is a Canadian software engineer, consultant and author, currently Practice Leader Agile Development at IBM Corporation in the IBM Methods group...

As a verb

As a verb, the software development methodology is an approach used by organizations and project teams to apply the software development methodology framework (noun). Specific software development methodologies (verb) include:

1970s

Structured programming
Structured programming
Structured programming is a programming paradigm aimed on improving the clarity, quality, and development time of a computer program by making extensive use of subroutines, block structures and for and while loops - in contrast to using simple tests and jumps such as the goto statement which could...

since 1969
Cap Gemini SDM
Cap Gemini SDM
Cap Gemini SDM, or SDM2 is a software development method developed by the software company PANDATA in the Netherlands in 1970. The method is a waterfall model divided in seven phases that have a clear start and end. Each phase delivers products, called milestones...

, originally from PANDATA, the first English translation was published in 1974. SDM stands for System Development Methodology

1980s

Structured Systems Analysis and Design Methodology (SSADM) from 1980 onwards
Information Requirement Analysis/Soft systems methodology

1990s

Object-oriented programming
Object-oriented programming
Object-oriented programming is a programming paradigm using "objects" – data structures consisting of data fields and methods together with their interactions – to design applications and computer programs. Programming techniques may include features such as data abstraction,...

(OOP) has been developed since the early 1960s, and developed as a dominant programming approach during the mid-1990s
Rapid application development
Rapid application development
Rapid application development is a software development methodology that uses minimal planning in favor of rapid prototyping. The "planning" of software developed using RAD is interleaved with writing the software itself...

(RAD) since 1991
Scrum
Scrum (development)
Scrum is an iterative, incremental framework for project management often seen in agile software development, a type of software engineering....

, since the late 1990s
Team software process
Team Software Process
In combination with the Personal Software Process , the Team Software Process provides a defined operational process framework that is designed to help teams of managers and engineers organize projects and produce software products that range in size of sizes beyond from small projects of several...

developed by Watts Humphrey at the SEI
Sei
Sei can refer to:*Sei whale*Sei Ashina, an actress*Seri language, sei is the ISO 639-code of that language*6 , sei is the Italian word for six *Endpoint_interface, service endpoint interface...
Extreme Programming
Extreme Programming
Extreme programming is a software development methodology which is intended to improve software quality and responsiveness to changing customer requirements...

since 1999

Verb approaches

Every software development methodology framework acts as a basis for applying specific approaches to develop and maintain software. Several software development approaches have been used since the origin of information technology. These are:

Waterfall: a linear framework
Prototyping: an iterative framework
Incremental: a combined linear-iterative framework
Spiral: a combined linear-iterative framework
Rapid application development (RAD): an iterative framework
Extreme Programming

Waterfall development

The Waterfall model

Waterfall model

The waterfall model is a sequential design process, often used in software development processes, in which progress is seen as flowing steadily downwards through the phases of Conception, Initiation, Analysis, Design, Construction, Testing, Production/Implementation and Maintenance.The waterfall...

is a sequential development approach, in which development is seen as flowing steadily downwards (like a waterfall) through the phases of requirements analysis, design, implementation, testing (validation), integration, and maintenance. The first formal description of the method is often cited as an article published by Winston W. Royce

Winston W. Royce

Winston W. Royce was an American computer scientist, director at Lockheed Software Technology Center in Austin, Texas, and one of the leaders in software development in the second half of the 20th century...

in 1970 although Royce did not use the term "waterfall" in this article.

The basic principles are:

Project is divided into sequential phases, with some overlap and splashback acceptable between phases.
Emphasis is on planning, time schedules, target dates, budgets and implementation of an entire system at one time.
Tight control is maintained over the life of the project via extensive written documentation, formal reviews, and approval/signoff by the user and information technology management occurring at the end of most phases before beginning the next phase.

The Waterfall model is a traditional engineering approach applied to software engineering. It has been widely blamed for several large-scale government projects running over budget, over time and sometimes failing to deliver on requirements due to the Big Design Up Front

Big Design Up Front

Big Design Up Front is a term for any software development approach in which the program's design is to be completed and perfected before that program's implementation is started...

approach. Except when contractually required, the Waterfall model has been largely superseded by more flexible and versatile methodologies developed specifically for software development. See Criticism of Waterfall model.

Prototyping

Software prototyping

*Software prototyping, refers to the activity of creating prototypes of software applications, i.e., incomplete versions of the software program being developed...

, is the development approach of activities during software development

Software development

Software development is the development of a software product...

, the creation of prototypes, i.e., incomplete versions of the software program being developed.

The basic principles are:

Not a standalone, complete development methodology, but rather an approach to handling selected parts of a larger, more traditional development methodology (i.e. incremental, spiral, or rapid application development (RAD)).
Attempts to reduce inherent project risk by breaking a project into smaller segments and providing more ease-of-change during the development process.
User is involved throughout the development process, which increases the likelihood of user acceptance of the final implementation.
Small-scale mock-ups of the system are developed following an iterative modification process until the prototype evolves to meet the users’ requirements.
While most prototypes are developed with the expectation that they will be discarded, it is possible in some cases to evolve from prototype to working system.
A basic understanding of the fundamental business problem is necessary to avoid solving the wrong problem.

Incremental development

Various methods are acceptable for combining linear and iterative systems development methodologies, with the primary objective of each being to reduce inherent project risk by breaking a project into smaller segments and providing more ease-of-change during the development process.

The basic principles are:

A series of mini-Waterfalls are performed, where all phases of the Waterfall are completed for a small part of a system, before proceeding to the next increment, or
Overall requirements are defined before proceeding to evolutionary, mini-Waterfall development of individual increments of a system, or
The initial software concept, requirements analysis, and design of architecture and system core are defined via Waterfall, followed by iterative Prototyping, which culminates in installing the final prototype, a working system.

Spiral development

The spiral model

Spiral model

The spiral model is a software development process combining elements of both design and prototyping-in-stages, in an effort to combine advantages of top-down and bottom-up concepts. Also known as the spiral lifecycle model , it is a systems development method used in information technology...

is a software development process

Software development process

combining elements of both design

Design

Design as a noun informally refers to a plan or convention for the construction of an object or a system while “to design” refers to making this plan...

and prototyping-in-stages, in an effort to combine advantages of top-down and bottom-up

Top-down and bottom-up design

Top–down and bottom–up are strategies of information processing and knowledge ordering, mostly involving software, but also other humanistic and scientific theories . In practice, they can be seen as a style of thinking and teaching...

concepts. It is a meta-model, a model that can be used by other models.

The basic principles are:

Focus is on risk assessment and on minimizing project risk by breaking a project into smaller segments and providing more ease-of-change during the development process, as well as providing the opportunity to evaluate risks and weigh consideration of project continuation throughout the life cycle.
"Each cycle involves a progression through the same sequence of steps, for each part of the product and for each of its levels of elaboration, from an overall concept-of-operation document down to the coding of each individual program."
Each trip around the spiral traverses four basic quadrants: (1) determine objectives, alternatives, and constraints of the iteration; (2) evaluate alternatives; Identify and resolve risks; (3) develop and verify deliverables from the iteration; and (4) plan the next iteration.
Begin each cycle with an identification of stakeholders and their win conditions, and end each cycle with review and commitment.

Rapid application development

Rapid application development is a software development methodology that uses minimal planning in favor of rapid prototyping. The "planning" of software developed using RAD is interleaved with writing the software itself...

(RAD) is a software development methodology, which involves iterative development and the construction of prototype

Prototype

A prototype is an early sample or model built to test a concept or process or to act as a thing to be replicated or learned from.The word prototype derives from the Greek πρωτότυπον , "primitive form", neutral of πρωτότυπος , "original, primitive", from πρῶτος , "first" and τύπος ,...

s. Rapid application development is a term originally used to describe a software development process

Software development process

introduced by James Martin

James Martin (author)

James Martin is a British Information Technology consultant and author, who was nominated for a Pulitzer prize for his book, The Wired Society: A Challenge for Tomorrow .- Biography :...

in 1991.

The basic principles are:

Key objective is for fast development and delivery of a high quality system at a relatively low investment cost.
Attempts to reduce inherent project risk by breaking a project into smaller segments and providing more ease-of-change during the development process.
Aims to produce high quality systems quickly, primarily via iterative Prototyping (at any stage of development), active user involvement, and computerized development tools. These tools may include Graphical User Interface
Graphical user interface
In computing, a graphical user interface is a type of user interface that allows users to interact with electronic devices with images rather than text commands. GUIs can be used in computers, hand-held devices such as MP3 players, portable media players or gaming devices, household appliances and...

(GUI) builders, Computer Aided Software Engineering (CASE) tools, Database Management System
Database management system
A database management system is a software package with computer programs that control the creation, maintenance, and use of a database. It allows organizations to conveniently develop databases for various applications by database administrators and other specialists. A database is an integrated...

s (DBMS), fourth-generation programming language
Fourth-generation programming language
A fourth-generation programming language is a programming language or programming environment designed with a specific purpose in mind, such as the development of commercial business software. In the history of computer science, the 4GL followed the 3GL in an upward trend toward higher...

s, code generators, and object-oriented techniques.
Key emphasis is on fulfilling the business need, while technological or engineering excellence is of lesser importance.
Project control involves prioritizing development and defining delivery deadlines or “timeboxes”. If the project starts to slip, emphasis is on reducing requirements to fit the timebox, not in increasing the deadline.
Generally includes joint application design
Joint application design
Joint application design is a process used in the prototyping life cycle area of the Dynamic Systems Development Method to collect business requirements while developing new information systems for a company...

(JAD), where users are intensely involved in system design, via consensus building in either structured workshops, or electronically facilitated interaction.
Active user involvement is imperative.
Iteratively produces production software, as opposed to a throwaway prototype.
Produces documentation necessary to facilitate future development and maintenance.
Standard systems analysis and design methods can be fitted into this framework.

Other practices

Other methodology practices include:

Object-oriented development methodologies, such as Grady Booch's object-oriented design (OOD), also known as object-oriented analysis and design (OOAD). The Booch model includes six diagrams: class, object, state transition, interaction, module, and process.
Top-down programming: evolved in the 1970s by IBM researcher Harlan Mills
Harlan Mills
Harlan D. Mills was Professor of Computer Science at the Florida Institute of Technology and founder of Software Engineering Technology, Inc. of Vero Beach, Florida . Mills' contributions to software engineering have had a profound and enduring effect on education and industrial practice. Since...

(and Niklaus Wirth
Niklaus Wirth
Niklaus Emil Wirth is a Swiss computer scientist, best known for designing several programming languages, including Pascal, and for pioneering several classic topics in software engineering. In 1984 he won the Turing Award for developing a sequence of innovative computer languages.-Biography:Wirth...

) in developed structured programming
Structured programming
Structured programming is a programming paradigm aimed on improving the clarity, quality, and development time of a computer program by making extensive use of subroutines, block structures and for and while loops - in contrast to using simple tests and jumps such as the goto statement which could...

.
Unified Process
Unified Process
The Unified Software Development Process or Unified Process is a popular iterative and incremental software development process framework. The best-known and extensively documented refinement of the Unified Process is the Rational Unified Process ....

(UP) is an iterative software development methodology framework, based on Unified Modeling Language
Unified Modeling Language
Unified Modeling Language is a standardized general-purpose modeling language in the field of object-oriented software engineering. The standard is managed, and was created, by the Object Management Group...

(UML). UP organizes the development of software into four phases, each consisting of one or more executable iterations of the software at that stage of development: inception, elaboration, construction, and guidelines. Many tools and products exist to facilitate UP implementation. One of the more popular versions of UP is the Rational Unified Process
Rational Unified Process
The Rational Unified Process is an iterative software development process framework created by the Rational Software Corporation, a division of IBM since 2003...

(RUP).
Agile software development
Agile software development
Agile software development is a group of software development methodologies based on iterative and incremental development, where requirements and solutions evolve through collaboration between self-organizing, cross-functional teams...

refers to a group of software development methodologies based on iterative development, where requirements and solutions evolve via collaboration between self-organizing cross-functional teams. The term was coined in the year 2001 when the Agile Manifesto was formulated.

View model

A view model

View model

A view model or viewpoints framework in systems engineering, software engineering, and enterprise engineering is a framework which defines a coherent set of views to be used in the construction of a system architecture, software architecture, or enterprise architecture. A view is a representation...

is framework which provides the viewpoint

Viewpoint

Viewpoint may refer to:* A camera angle in photography, filmmaking, and other visual arts* Viewpoint model, a computer science technique for making complex systems more comprehensible to human engineers* Viewpoint , shooter video game...

s on the system

System

System is a set of interacting or interdependent components forming an integrated whole....

and its environment

Environment (systems)

In science and engineering, a system is the part of the universe that is being studied, while the environment is the remainder of the universe that lies outside the boundaries of the system. It is also known as the surroundings, and in thermodynamics, as the reservoir...

, to be used in the software development process

Software development process

. It is a graphical representation of the underlying semantics of a view

View

A view is what can be seen in a range of vision. View may also be used as a synonym of point of view in the first sense. View may also be used figuratively or with special significance—for example, to imply a scenic outlook or significant vantage point:...

.

The purpose of viewpoints and views is to enable human engineers to comprehend very complex system

Complex system

A complex system is a system composed of interconnected parts that as a whole exhibit one or more properties not obvious from the properties of the individual parts....

s, and to organize the elements of the problem and the solution around domains of expertise. In the engineering

Engineering

Engineering is the discipline, art, skill and profession of acquiring and applying scientific, mathematical, economic, social, and practical knowledge, in order to design and build structures, machines, devices, systems, materials and processes that safely realize improvements to the lives of...

of physically intensive systems, viewpoints often correspond to capabilities and responsibilities within the engineering organization.

Most complex system specifications are so extensive that no one individual can fully comprehend all aspects of the specifications. Furthermore, we all have different interests in a given system and different reasons for examining the system

System

System is a set of interacting or interdependent components forming an integrated whole....

's specifications. A business

Business

A business is an organization engaged in the trade of goods, services, or both to consumers. Businesses are predominant in capitalist economies, where most of them are privately owned and administered to earn profit to increase the wealth of their owners. Businesses may also be not-for-profit...

executive will ask different questions of a system make-up than would a system implementer. The concept of viewpoints framework, therefore, is to provide separate viewpoints into the specification of a given complex system. These viewpoints each satisfy an audience with interest in some set of aspects of the system. Associated with each viewpoint is a viewpoint language
that optimizes the vocabulary and presentation for the audience of that viewpoint.

Business process and data modelling

Graphical representation of the current state of information provides a very effective means for presenting information to both users and system developer

Software developer

A software developer is a person concerned with facets of the software development process. Their work includes researching, designing, developing, and testing software. A software developer may take part in design, computer programming, or software project management...

A business model
Business model
A business model describes the rationale of how an organization creates, delivers, and captures value...

illustrates the functions associated with the business process being modeled and the organizations that perform these functions. By depicting activities and information flows, a foundation is created to visualize, define, understand, and validate the nature of a process.
A data model
Data model
A data model in software engineering is an abstract model, that documents and organizes the business data for communication between team members and is used as a plan for developing applications, specifically how data is stored and accessed....

provides the details of information to be stored, and is of primary use when the final product is the generation of computer software code for an application or the preparation of a functional specification to aid a computer software make-or-buy decision. See the figure on the right for an example of the interaction between business process and data models.

Usually, a model is created after conducting an interview, referred to as business analysis

Business Analysis

Business analysis is the discipline of identifying business needs and determining solutions to business problems. Solutions often include a systems development component, but may also consist of process improvement, organizational change or strategic planning and policy development...

. The interview consists of a facilitator asking a series of questions designed to extract required information that describes a process. The interviewer is called a facilitator to emphasize that it is the participants who provide the information. The facilitator should have some knowledge of the process of interest, but this is not as important as having a structured methodology by which the questions are asked of the process expert. The methodology is
important because usually a team of facilitators is collecting information across the facility and the results of the information from all the interviewers must fit together once completed.

The models are developed as defining either the current state of the process, in which case the final product is called the "as-is" snapshot model, or a collection of ideas of what the process should contain, resulting in a "what-can-be" model. Generation of process and data models can be used to determine if the existing processes and information systems are sound and only need minor modifications or enhancements, or if re-engineering is required as a corrective action. The creation of business models is more than a way to view or automate your information process. Analysis can be used to fundamentally reshape the way your business or organization conducts its operations.

Computer-aided software engineering

Computer-aided software engineering is the scientific application of a set of tools and methods to a software system which is meant to result in high-quality, defect-free, and maintainable software products...

(CASE), in the field software engineering

Software engineering

is the scientific application of a set of tools and methods to a software which results in high-quality, defect-free, and maintainable software products. It also refers to methods for the development of information system

Information system

s together with automated tools that can be used in the software development process

Software development process

. The term "computer-aided software engineering" (CASE) can refer to the software used for the automated development of systems software, i.e., computer code. The CASE functions include analysis, design, and programming. CASE tools automate methods for designing, documenting, and producing structured computer code in the desired programming language

Programming language

A programming language is an artificial language designed to communicate instructions to a machine, particularly a computer. Programming languages can be used to create programs that control the behavior of a machine and/or to express algorithms precisely....

.

Two key ideas of Computer-aided Software System Engineering (CASE) are:

Foster computer assistance in software development
Software development
Software development is the development of a software product...

and or software maintenance
Software maintenance
Software Maintenance in software engineering is the modification of a software product after delivery to correct faults, to improve performance or other attributes....

processes, and
An engineering approach to software development and or maintenance.

Typical CASE tools exist for configuration management

Configuration management

Configuration management is a field of management that focuses on establishing and maintaining consistency of a system or product's performance and its functional and physical attributes with its requirements, design, and operational information throughout its life.For information assurance, CM...

, data modeling

Data modeling

Data modeling in software engineering is the process of creating a data model for an information system by applying formal data modeling techniques.- Overview :...

, model transformation

Model transformation

A model transformation, in model-driven engineering, is an automatable way of ensuring that a family of models is consistent, in a precise sense which the software engineer can define...

, refactoring

Refactoring

Code refactoring is "disciplined technique for restructuring an existing body of code, altering its internal structure without changing its external behavior", undertaken in order to improve some of the nonfunctional attributes of the software....

, source code generation, and Unified Modeling Language

Unified Modeling Language

Unified Modeling Language is a standardized general-purpose modeling language in the field of object-oriented software engineering. The standard is managed, and was created, by the Object Management Group...

Integrated development environment

An integrated development environment

Integrated development environment

An integrated development environment is a software application that provides comprehensive facilities to computer programmers for software development...

(IDE) also known as integrated design environment or integrated debugging environment is a software application that provides comprehensive facilities to computer programmers for software development. An IDE normally consists of a:

source code editor
Source code editor
A source code editor is a text editor program designed specifically for editing source code of computer programs by programmers. It may be a standalone application or it may be built into an integrated development environment ....

,
compiler
Compiler
A compiler is a computer program that transforms source code written in a programming language into another computer language...

and/or interpreter
Interpreter (computing)
In computer science, an interpreter normally means a computer program that executes, i.e. performs, instructions written in a programming language...

,
build automation
Build Automation
Build automation is the act of scripting or automating a wide variety of tasks that software developers do in their day-to-day activities including things like:* compiling computer source code into binary code* packaging binary code* running tests...

tools, and
debugger
Debugger
A debugger or debugging tool is a computer program that is used to test and debug other programs . The code to be examined might alternatively be running on an instruction set simulator , a technique that allows great power in its ability to halt when specific conditions are encountered but which...

(usually).

IDEs are designed to maximize programmer productivity by providing tight-knit components with similar user interface

User interface

The user interface, in the industrial design field of human–machine interaction, is the space where interaction between humans and machines occurs. The goal of interaction between a human and a machine at the user interface is effective operation and control of the machine, and feedback from the...

s. Typically an IDE is dedicated to a specific programming language

Programming language

, so as to provide a feature set which most closely matches the programming paradigm

Programming paradigm

A programming paradigm is a fundamental style of computer programming. Paradigms differ in the concepts and abstractions used to represent the elements of a program and the steps that compose a computation A programming paradigm is a fundamental style of computer programming. (Compare with a...

s of the language.

Modeling language

A modeling language

Modeling language

A modeling language is any artificial language that can be used to express information or knowledge or systems in a structure that is defined by a consistent set of rules...

is any artificial language that can be used to express information

Information

Information in its most restricted technical sense is a message or collection of messages that consists of an ordered sequence of symbols, or it is the meaning that can be interpreted from such a message or collection of messages. Information can be recorded or transmitted. It can be recorded as...

or knowledge

Knowledge

Knowledge is a familiarity with someone or something unknown, which can include information, facts, descriptions, or skills acquired through experience or education. It can refer to the theoretical or practical understanding of a subject...

or system

System

System is a set of interacting or interdependent components forming an integrated whole....

s in a structure

Structure

Structure is a fundamental, tangible or intangible notion referring to the recognition, observation, nature, and permanence of patterns and relationships of entities. This notion may itself be an object, such as a built structure, or an attribute, such as the structure of society...

that is defined by a consistent set of rules. The rules are used for interpretation of the meaning of components in the structure. A modeling language can be graphical or textual. Graphical modeling languages use a diagram techniques with named symbols that represent concepts and lines that connect the symbols and that represent relationships and various other graphical annotation to represent constraints. Textual modeling languages typically use standardised keywords accompanied by parameters to make computer-interpretable expressions.

Example of graphical modelling languages in the field of software engineering are:

Business Process Modeling Notation
Business Process Modeling Notation
Business Process Model and Notation is a graphical representation for specifying business processes in a business process model. It was previously known as Business Process Modeling Notation....

(BPMN, and the XML
XML
Extensible Markup Language is a set of rules for encoding documents in machine-readable form. It is defined in the XML 1.0 Specification produced by the W3C, and several other related specifications, all gratis open standards....

form BPML) is an example of a process modeling
Process modeling
The term process model is used in various contexts. For example, in business process modeling the enterprise process model is often referred to as the business process model. Process models are core concepts in the discipline of process engineering....

language.
EXPRESS and EXPRESS-G (ISO 10303-11) is an international standard general-purpose data modeling
Data modeling
Data modeling in software engineering is the process of creating a data model for an information system by applying formal data modeling techniques.- Overview :...

language.
Extended Enterprise Modeling Language
Extended Enterprise Modeling Language
Extended Enterprise Modeling Language in software engineering is a modelling language used for Enterprise modelling across a number of layers.-Overview:...

(EEML) is commonly used for business process modeling across layers.
Flowchart
Flowchart
A flowchart is a type of diagram that represents an algorithm or process, showing the steps as boxes of various kinds, and their order by connecting these with arrows. This diagrammatic representation can give a step-by-step solution to a given problem. Process operations are represented in these...

is a schematic representation of an algorithm or a stepwise process,
Fundamental Modeling Concepts
Fundamental modeling concepts
Fundamental Modeling Concepts provide a framework to describe software-intensive systems. It strongly emphasizes the communication about software-intensive systems by using a semi-formal graphical notation that can easily be understood.- Introduction :...

(FMC) modeling language for software-intensive systems.
IDEF
IDEF
IDEF, an abbreviation of Integration Definition, refers to a family of modeling languages in the field of systems and software engineering. They cover a wide range of uses, from functional modeling to data, simulation, object-oriented analysis/design and knowledge acquisition. These "definition...

is a family of modeling languages, the most notable of which include IDEF0
IDEF0
IDEF0 is a function modeling methodology for describing manufacturing functions, which offers a functional modeling language for the analysis, development, reengineering, and integration of information systems; business processes; or software engineering analysis.IDEF0 is part of the IDEF family...

for functional modeling, IDEF1X
IDEF1X
IDEF1X is a data modeling language for the developing of semantic data models. IDEF1X is used to produce a graphical information model which represents the structure and semantics of information within an environment or system.IDEF1X permits the construction of semantic data models which may serve...

for information modeling, and IDEF5
IDEF5
IDEF5 is a software engineering method to develop and maintain usable, accurate, domain ontologies...

for modeling ontologies.
LePUS3
Lepus3
LePUS3 is a language for modelling and visualizing object-oriented programs and design patterns. It is defined as a formal specification language, formulated as an axiomatized subset of First-order predicate logic. A diagram in LePUS3 is also called a Codechart...

is an object-oriented visual Design Description Language and a formal specification
Formal specification
In computer science, a formal specification is a mathematical description of software or hardware that may be used to develop an implementation. It describes what the system should do, not how the system should do it...

language that is suitable primarily for modelling large object-oriented (Java
Java (programming language)
Java is a programming language originally developed by James Gosling at Sun Microsystems and released in 1995 as a core component of Sun Microsystems' Java platform. The language derives much of its syntax from C and C++ but has a simpler object model and fewer low-level facilities...

, C++
C++
C++ is a statically typed, free-form, multi-paradigm, compiled, general-purpose programming language. It is regarded as an intermediate-level language, as it comprises a combination of both high-level and low-level language features. It was developed by Bjarne Stroustrup starting in 1979 at Bell...

, C#) programs and design patterns
Design Patterns
Design Patterns: Elements of Reusable Object-Oriented Software is a software engineering book describing recurring solutions to common problems in software design. The book's authors are Erich Gamma, Richard Helm, Ralph Johnson and John Vlissides with a foreword by Grady Booch. The authors are...

.
Specification and Description Language
Specification and Description Language
Specification and Description Language is a specification language targeted at the unambiguous specification and description of the behaviour of reactive and distributed systems.- Overview :It is defined by the ITU-T...

(SDL) is a specification language targeted at the unambiguous specification and description of the behaviour of reactive and distributed systems.
Unified Modeling Language
Unified Modeling Language
Unified Modeling Language is a standardized general-purpose modeling language in the field of object-oriented software engineering. The standard is managed, and was created, by the Object Management Group...

(UML) is a general-purpose modeling
General-purpose modeling
General-purpose modeling is the systematic use of a general-purpose modeling language to represent the various facets of an object or a system...

language that is an industry standard for specifying software-intensive systems. UML 2.0, the current version, supports thirteen different diagram techniques, and has widespread tool support.

Not all modeling languages are executable, and for those that are, using them doesn't necessarily mean that programmers are no longer needed. On the contrary, executable modeling languages are intended to amplify the productivity of skilled programmers, so that they can address more difficult problems, such as parallel computing

Parallel computing

Parallel computing is a form of computation in which many calculations are carried out simultaneously, operating on the principle that large problems can often be divided into smaller ones, which are then solved concurrently . There are several different forms of parallel computing: bit-level,...

and distributed systems.

Programming paradigm

A programming paradigm

Programming paradigm

is a fundamental style of computer programming

Computer programming

Computer programming is the process of designing, writing, testing, debugging, and maintaining the source code of computer programs. This source code is written in one or more programming languages. The purpose of programming is to create a program that performs specific operations or exhibits a...

, in contrast to a software engineering methodology, which is a style of solving specific software engineering

Software engineering

problems. Paradigms differ in the concepts and abstractions used to represent the elements of a program (such as objects, functions, variables, constraints...) and the steps that compose a computation (assignation, evaluation, continuations, data flows...).

A programming language

Programming language

can support multiple paradigms

Multi-paradigm programming language

Programming languages can be grouped by the number and types of paradigms supported.-Paradigm summaries:A concise reference for the programming paradigms listed in this article....

. For example programs written in C++

C++

C++ is a statically typed, free-form, multi-paradigm, compiled, general-purpose programming language. It is regarded as an intermediate-level language, as it comprises a combination of both high-level and low-level language features. It was developed by Bjarne Stroustrup starting in 1979 at Bell...

or Object Pascal

Object Pascal

Object Pascal refers to a branch of object-oriented derivatives of Pascal, mostly known as the primary programming language of Embarcadero Delphi.-Early history at Apple:...

can be purely procedural

Procedural programming

Procedural programming can sometimes be used as a synonym for imperative programming , but can also refer to a programming paradigm, derived from structured programming, based upon the concept of the procedure call...

, or purely object-oriented

Object-oriented programming

Object-oriented programming is a programming paradigm using "objects" – data structures consisting of data fields and methods together with their interactions – to design applications and computer programs. Programming techniques may include features such as data abstraction,...

, or contain elements of both paradigms. Software designers and programmers decide how to use those paradigm elements. In object-oriented programming

Object-oriented programming

, programmers can think of a program as a collection of interacting objects, while in functional programming

Functional programming

In computer science, functional programming is a programming paradigm that treats computation as the evaluation of mathematical functions and avoids state and mutable data. It emphasizes the application of functions, in contrast to the imperative programming style, which emphasizes changes in state...

a program can be thought of as a sequence of stateless function evaluations. When programming computers or systems with many processors, process-oriented programming

Process-oriented programming

Process-oriented programming is a programming paradigm that separates the concerns of data structures and the concurrent processes that act upon them. The data structures in this case are typically persistent, complex, and large scale - the subject of general purpose applications, as opposed to...

allows programmers to think about applications as sets of concurrent processes acting upon logically shared data structures.

Just as different groups in software engineering

Software engineering

advocate different methodologies, different programming language

Programming language

s advocate different programming paradigms. Some languages are designed to support one paradigm (Smalltalk

Smalltalk

Smalltalk is an object-oriented, dynamically typed, reflective programming language. Smalltalk was created as the language to underpin the "new world" of computing exemplified by "human–computer symbiosis." It was designed and created in part for educational use, more so for constructionist...

supports object-oriented programming, Haskell

Haskell (programming language)

Haskell is a standardized, general-purpose purely functional programming language, with non-strict semantics and strong static typing. It is named after logician Haskell Curry. In Haskell, "a function is a first-class citizen" of the programming language. As a functional programming language, the...

supports functional programming), while other programming languages support multiple paradigms (such as Object Pascal

Object Pascal

Object Pascal refers to a branch of object-oriented derivatives of Pascal, mostly known as the primary programming language of Embarcadero Delphi.-Early history at Apple:...

, C++

C++

, C#, Visual Basic

Visual Basic

Visual Basic is the third-generation event-driven programming language and integrated development environment from Microsoft for its COM programming model...

, Common Lisp

Common Lisp

Common Lisp, commonly abbreviated CL, is a dialect of the Lisp programming language, published in ANSI standard document ANSI INCITS 226-1994 , . From the ANSI Common Lisp standard the Common Lisp HyperSpec has been derived for use with web browsers...

, Scheme, Python

Python (programming language)

Python is a general-purpose, high-level programming language whose design philosophy emphasizes code readability. Python claims to "[combine] remarkable power with very clear syntax", and its standard library is large and comprehensive...

, Ruby

Ruby (programming language)

Ruby is a dynamic, reflective, general-purpose object-oriented programming language that combines syntax inspired by Perl with Smalltalk-like features. Ruby originated in Japan during the mid-1990s and was first developed and designed by Yukihiro "Matz" Matsumoto...

, and Oz

Oz (programming language)

Oz is a multiparadigm programming language, developed in the Programming Systems Lab at Université catholique de Louvain, for programming language education. It has a canonical textbook: Concepts, Techniques, and Models of Computer Programming....

).

Many programming paradigms are as well known for what methods they forbid as for what they enable. For instance, pure functional programming forbids using side-effects; structured programming

Structured programming

Structured programming is a programming paradigm aimed on improving the clarity, quality, and development time of a computer program by making extensive use of subroutines, block structures and for and while loops - in contrast to using simple tests and jumps such as the goto statement which could...

forbids using goto

Goto

goto is a statement found in many computer programming languages. It is a combination of the English words go and to. It performs a one-way transfer of control to another line of code; in contrast a function call normally returns control...

statements. Partly for this reason, new paradigms are often regarded as doctrinaire or overly rigid by those accustomed to earlier styles. Avoiding certain methods can make it easier to prove theorems about a program's correctness, or simply to understand its behavior.

Software framework

A software framework

Software framework

In computer programming, a software framework is an abstraction in which software providing generic functionality can be selectively changed by user code, thus providing application specific software...

is a re-usable design for a software system or subsystem. A software framework may include support programs, code libraries

Library (computer science)

In computer science, a library is a collection of resources used to develop software. These may include pre-written code and subroutines, classes, values or type specifications....

, a scripting language

Scripting language

A scripting language, script language, or extension language is a programming language that allows control of one or more applications. "Scripts" are distinct from the core code of the application, as they are usually written in a different language and are often created or at least modified by the...

, or other software to help develop and glue together the different components of a software project. Various parts of the framework may be exposed via an API

Application programming interface

An application programming interface is a source code based specification intended to be used as an interface by software components to communicate with each other...

Software development process

A software development process

Software development process

is a framework imposed on the development of a software product. Synonyms include software life cycle

ISO 12207

ISO/IEC 12207 Systems and software engineering — Software life cycle processes is an international standard for software lifecycle processes...

and software process. There are several models for such processes, each describing approaches to a variety of tasks or activities that take place during the process.

A largely growing body of software development

Software development

Software development is the development of a software product...

organizations implement process methodologies. Many of them are in the defense industry

Defense industry

The defense industry, also called the military industry, comprises government and commercial industry involved in research, development, production, and service of military materiel, equipment and facilities...

, which in the U.S. requires a rating based on 'process models' to obtain contracts. The international standard describing the method to select, implement and monitor the life cycle for software is ISO 12207

ISO 12207

ISO/IEC 12207 Systems and software engineering — Software life cycle processes is an international standard for software lifecycle processes...

.

A decades-long goal has been to find repeatable, predictable processes that improve productivity and quality. Some try to systematize or formalize the seemingly unruly task of writing software. Others apply project management methods to writing software. Without project management, software projects can easily be delivered late or over budget. With large numbers of software projects not meeting their expectations in terms of functionality, cost, or delivery schedule, effective project management appears to be lacking.

External links

Selecting a development approach at cms.hhs.gov.
Software Methodologies Book Reviews An extensive set of book reviews related to software methodologies and processes

The source of this article is wikipedia, the free encyclopedia. The text of this article is licensed under the GFDL.

History

As a noun

As a verb

Verb approaches

Waterfall development

Prototyping

Incremental development

Spiral development

Rapid application development

Other practices

View model

Business process and data modelling

Computer-aided software engineering

Integrated development environment

Modeling language

Programming paradigm

Software framework

Software development process

See also

External links