Software development process

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In software engineering, a software development process or software development life cycle (SDLC) is a process of planning and managing software development. It typically involves dividing software development work into smaller, parallel, or sequential steps or sub-processes to improve design and/or product management. The methodology may include the pre-definition of specific deliverables and artifacts that are created and completed by a project team to develop or maintain an application. [1]

Contents

Most modern development processes can be vaguely described as agile. Other methodologies include waterfall, prototyping, iterative and incremental development, spiral development, rapid application development, and extreme programming.

A life-cycle "model" is sometimes considered a more general term for a category of methodologies and a software development "process" is a particular instance as adopted by a specific organization. [ citation needed ] For example, there are many specific software development processes that fit the spiral life-cycle model. The field is often considered a subset of the systems development life cycle.

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 (SDLC) can be considered to be the oldest formalized methodology framework for building information systems. 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––from the inception of the idea to delivery of the final system––to be carried out rigidly and sequentially" [2] 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 and number crunching routines". [2]

Requirements gathering and analysis: The first phase of the custom software development process involves understanding the client's requirements and objectives. This stage typically involves engaging in thorough discussions and conducting interviews with stakeholders to identify the desired features, functionalities, and overall scope of the software. The development team works closely with the client to analyze existing systems and workflows, determine technical feasibility, and define project milestones.

Planning and design: Once the requirements are understood, the custom software development team proceeds to create a comprehensive project plan. This plan outlines the development roadmap, including timelines, resource allocation, and deliverables. The software architecture and design are also established during this phase. User interface (UI) and user experience (UX) design elements are considered to ensure the software's usability, intuitiveness, and visual appeal.

Development: With the planning and design in place, the development team begins the coding process. This phase involves writing, testing, and debugging the software code. Agile methodologies, such as scrum or kanban, are often employed to promote flexibility, collaboration, and iterative development. Regular communication between the development team and the client ensures transparency and enables quick feedback and adjustments.

Testing and quality assurance: To ensure the software's reliability, performance, and security, rigorous testing and quality assurance (QA) processes are carried out. Different testing techniques, including unit testing, integration testing, system testing, and user acceptance testing, are employed to identify and rectify any issues or bugs. QA activities aim to validate the software against the predefined requirements, ensuring that it functions as intended.

Deployment and implementation: Once the software passes the testing phase, it is ready for deployment and implementation. The development team assists the client in setting up the software environment, migrating data if necessary, and configuring the system. User training and documentation are also provided to ensure a smooth transition and enable users to maximize the software's potential.

Maintenance and support: After the software is deployed, ongoing maintenance and support become crucial to address any issues, enhance performance, and incorporate future enhancements. Regular updates, bug fixes, and security patches are released to keep the software up-to-date and secure. This phase also involves providing technical support to end users and addressing their queries or concerns. Methodologies, processes, and frameworks range from specific prescriptive steps that can be used directly by an organization in day-to-day work, to flexible frameworks that an organization uses to generate a custom set of steps tailored to the needs of a specific project or group. In some cases, a "sponsor" or "maintenance" organization distributes an official set of documents that describe the process. Specific examples include:

1970s
1980s
1990s
2000s

2010s

Since DSDM in 1994, all of the methodologies on the above list except RUP have been agile methodologies - yet many organizations, especially governments, still use pre-agile processes (often waterfall or similar). Software process and software quality are closely interrelated; some unexpected facets and effects have been observed in practice. [3]

Among these, another software development process has been established in open source. The adoption of these best practices known and established processes within the confines of a company is called inner source.

Prototyping

Software prototyping is about creating prototypes, i.e. incomplete versions of the software program being developed.

The basic principles are: [1]

A basic understanding of the fundamental business problem is necessary to avoid solving the wrong problems, but this is true for all software methodologies.

Methodologies

Agile development

"Agile software development" refers to a group of software development frameworks 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.

Agile software development uses iterative development as a basis but advocates a lighter and more people-centric viewpoint than traditional approaches. Agile processes fundamentally incorporate iteration and the continuous feedback that it provides to successively refine and deliver a software system.

The Agile model also includes the following software development processes: [4]

Continuous integration

Continuous integration is the practice of merging all developer working copies to a shared mainline several times a day. [5] Grady Booch first named and proposed CI in his 1991 method, [6] although he did not advocate integrating several times a day. Extreme programming (XP) adopted the concept of CI and did advocate integrating more than once per day – perhaps as many as tens of times per day.

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.

There are three main variants of incremental development: [1]

  1. 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
  2. Overall requirements are defined before proceeding to evolutionary, mini-waterfall development of individual increments of a system, or
  3. The initial software concept, requirements analysis, and design of architecture and system core are defined via waterfall, followed by incremental implementation, which culminates in installing the final version, a working system.

Rapid application development

Rapid Application Development (RAD) Model RADModel.JPG
Rapid Application Development (RAD) Model

Rapid application development (RAD) is a software development methodology, which favors iterative development and the rapid construction of prototypes instead of large amounts of up-front planning. The "planning" of software developed using RAD is interleaved with writing the software itself. The lack of extensive pre-planning generally allows software to be written much faster and makes it easier to change requirements.

The rapid development process starts with the development of preliminary data models and business process models using structured techniques. In the next stage, requirements are verified using prototyping, eventually to refine the data and process models. These stages are repeated iteratively; further development results in "a combined business requirements and technical design statement to be used for constructing new systems". [7]

The term was first used to describe a software development process introduced by James Martin in 1991. According to Whitten (2003), it is a merger of various structured techniques, especially data-driven information technology engineering, with prototyping techniques to accelerate software systems development. [7]

The basic principles of rapid application development are: [1]

Waterfall development

The activities of the software development process represented in the waterfall model. There are several other models to represent this process. Waterfall model.svg
The activities of the software development process represented in the waterfall model. There are several other models to represent this process.

The waterfall model is a sequential development approach, in which development is seen as flowing steadily downwards (like a waterfall) through several phases, typically:

The first formal description of the method is often cited as an article published by Winston W. Royce [8] in 1970, although Royce did not use the term "waterfall" in this article. Royce presented this model as an example of a flawed, non-working model. [9]

The basic principles are: [1]

The waterfall model is a traditional engineering approach applied to software engineering. A strict waterfall approach discourages revisiting and revising any prior phase once it is complete. [ according to whom? ] This "inflexibility" in a pure waterfall model has been a source of criticism by supporters of other more "flexible" models. 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 approach.[ according to whom? ] Except when contractually required, the waterfall model has been largely superseded by more flexible and versatile methodologies developed specifically for software development.[ according to whom? ] See Criticism of waterfall model.

Spiral development

Spiral model (Boehm, 1988) Spiral model (Boehm, 1988).svg
Spiral model (Boehm, 1988)

In 1988, Barry Boehm published a formal software system development "spiral model," which combines some key aspects of the waterfall model and rapid prototyping methodologies, in an effort to combine advantages of top-down and bottom-up concepts. It provided emphasis on a key area many felt had been neglected by other methodologies: deliberate iterative risk analysis, particularly suited to large-scale complex systems.

The basic principles are: [1]

Shape Up

Shape Up is a software development approach introduced by Basecamp in 2018. It is a set of principles and techniques that Basecamp developed internally to overcome the problem of projects dragging on with no clear end. Its primary target audience is remote teams. Shape Up has no estimation and velocity tracking, backlogs, or sprints, unlike waterfall, agile, or scrum. Instead, those concepts are replaced with appetite, betting, and cycles. As of 2022, besides Basecamp, notable organizations that have adopted Shape Up include UserVoice and Block. [13] [14]

Cycles

Through trial and error, Basecamp found that the ideal cycle length is 6 weeks. This 6 week's period is long enough to build a meaningful feature and still short enough to induce a sense of urgency.

Shaping

Shaping is the process of preparing work before being handed over to designers and engineers. Shaped work spells out the solution's main UI elements, identifies rabbit holes, and outlines clear scope boundaries. It is meant to be rough and to leave finer details for builders (designers and engineers) to solve, allowing the builders to exercise their creativity and make trade-offs. [15] Shaped work is documented in the form of a pitch using an online document solution that supports commenting, allowing team members to contribute technical information asynchronously. Such comments are crucial for uncovering hidden surprises that may derail the project.

Before a cycle begins, stakeholders hold a betting table, where pitches are reviewed. For each pitch, a decision is made to either bet on it or drop it. [16]

Appetite

The way Shape Up determines how much time is allocated to a project is diametrically opposed to other methodologies. Shape Up starts with an appetite (for example, 6 weeks) and ends with a solution design that can be delivered within this constraint. The appetite becomes a hard deadline for the project's builders. [17]

Building

Shape Up is a two-track system where shapers and builders work in parallel. Work that is being shaped in the current cycle may be given to designers and engineers to build in a future cycle.

Recognizing the technical uncertainties that come with building, progress is tracked using a chart that visualizes the metaphor of the hill, aptly named the hill chart. The uphill phase is where builders are still working out their approach, while the downhill is where unknowns have been eliminated. Builders proactively and asynchronously self-report progress using an interactive online hill chart on Basecamp or Jira, shifting focus from done or not-done statuses to unknown or solved problems. The use of a hill chart replaces the process of reporting linear statuses in a scrum or Kanban standup. [18] [19]

Advanced methodologies

Other high-level software project methodologies include:

Process meta-models

Some "process models" are abstract descriptions for evaluating, comparing, and improving the specific process adopted by an organization.

In practice

The three basic approaches applied to software development methodology frameworks Three software development patterns mashed together.svg
The three basic approaches applied to software development methodology frameworks

A 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 is best suited to specific kinds of projects, based on various technical, organizational, project, and team considerations. [1]

Software development organizations implement process methodologies to ease the process of development. Sometimes, contractors may require methodologies employed, an example is the U.S. defense industry, which requires a rating based on process models to obtain contracts. The international standard for describing the method of selecting, implementing, and monitoring the life cycle for software is ISO/IEC 12207.

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 designing software. Others apply project management techniques to designing software. Large numbers of software projects do not meet their expectations in terms of functionality, cost, or delivery schedule - see List of failed and overbudget custom software projects for some notable examples.

Organizations may create a Software Engineering Process Group (SEPG), which is the focal point for process improvement. Composed of line practitioners who have varied skills, the group is at the center of the collaborative effort of everyone in the organization who is involved with software engineering process improvement.

A particular development team may also agree to program environment details, such as which integrated development environment is used one or more dominant programming paradigms, programming style rules, or choice of specific software libraries or software frameworks. These details are generally not dictated by the choice of model or general methodology.

Software development life cycle (SDLC) SLDC.jpg
Software development life cycle (SDLC)

See also


Related Research Articles

The waterfall model is a breakdown of development 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. The approach is typical for certain areas of engineering design. In software development, it tends to be among the less iterative and flexible approaches, as progress flows in largely one direction through the phases of conception, initiation, analysis, design, construction, testing, deployment and maintenance. The waterfall model is the earliest SDLC approach that was used in software development.

<span class="mw-page-title-main">Spiral model</span> Software development process model

The spiral model is a risk-driven software development process model. Based on the unique risk patterns of a given project, the spiral model guides a team to adopt elements of one or more process models, such as incremental, waterfall, or evolutionary prototyping.

<span class="mw-page-title-main">Iterative and incremental development</span> Development methodology

Iterative and incremental development is any combination of both iterative design or iterative method and incremental build model for development.

The rational unified process (RUP) is an iterative software development process framework created by the Rational Software Corporation, a division of IBM since 2003. RUP is not a single concrete prescriptive process, but rather an adaptable process framework, intended to be tailored by the development organizations and software project teams that will select the elements of the process that are appropriate for their needs. RUP is a specific implementation of the Unified Process.

Rapid application development (RAD), also called rapid application building (RAB), is both a general term for adaptive software development approaches, and the name for James Martin's method of rapid development. In general, RAD approaches to software development put less emphasis on planning and more emphasis on an adaptive process. Prototypes are often used in addition to or sometimes even instead of design specifications.

<span class="mw-page-title-main">Systems development life cycle</span> Systems engineering terms

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 information system. The SDLC concept applies to a range of hardware and software configurations, as a system can be composed of hardware only, software only, or a combination of both. There are usually six stages in this cycle: requirement analysis, design, development and testing, implementation, documentation, and evaluation.

Web development is the work involved in developing a website for the Internet or an intranet. Web development can range from developing a simple single static page of plain text to complex web applications, electronic businesses, and social network services. A more comprehensive list of tasks to which Web development commonly refers, may include Web engineering, Web design, Web content development, client liaison, client-side/server-side scripting, Web server and network security configuration, and e-commerce development.

In software development, agile practices include requirements, discovery and solutions improvement through the collaborative effort of self-organizing and cross-functional teams with their customer(s)/end user(s). Popularized in the 2001 Manifesto for Agile Software Development, these values and principles were derived from, and underpin, a broad range of software development frameworks, including Scrum and Kanban.

<span class="mw-page-title-main">Dynamic systems development method</span>

Dynamic systems development method (DSDM) is an agile project delivery framework, initially used as a software development method. First released in 1994, DSDM originally sought to provide some discipline to the rapid application development (RAD) method. In later versions the DSDM Agile Project Framework was revised and became a generic approach to project management and solution delivery rather than being focused specifically on software development and code creation and could be used for non-IT projects. The DSDM Agile Project Framework covers a wide range of activities across the whole project lifecycle and includes strong foundations and governance, which set it apart from some other Agile methods. The DSDM Agile Project Framework is an iterative and incremental approach that embraces principles of Agile development, including continuous user/customer involvement.

Software prototyping is the activity of creating prototypes of software applications, i.e., incomplete versions of the software program being developed. It is an activity that can occur in software development and is comparable to prototyping as known from other fields, such as mechanical engineering or manufacturing.

Cowboy coding is software development where programmers have autonomy over the development process. This includes control of the project's schedule, languages, algorithms, tools, frameworks and coding style. Typically, little to no coordination exists with other developers or stakeholders.

Microsoft Solutions Framework (MSF) is a set of principles, models, disciplines, concepts, and guidelines for delivering information technology services from Microsoft. MSF is not limited to developing applications only; it is also applicable to other IT projects like deployment, networking or infrastructure projects. MSF does not force the developer to use a specific methodology.

Object-oriented analysis and design (OOAD) is a technical approach for analyzing and designing an application, system, or business by applying object-oriented programming, as well as using visual modeling throughout the software development process to guide stakeholder communication and product quality.

The incremental build model is a method of software development where the product is designed, implemented and tested incrementally until the product is finished. It involves both development and maintenance. The product is defined as finished when it satisfies all of its requirements. This model combines the elements of the waterfall model with the iterative philosophy of prototyping. According to the Project Management Institute, an incremental approach is an "adaptive development approach in which the deliverable is produced successively, adding functionality until the deliverable contains the necessary and sufficient capability to be considered complete."

<span class="mw-page-title-main">Unified Process</span> Object oriented software development process framework

The unified software development process or unified process is an iterative and incremental software development process framework. The best-known and extensively documented refinement of the unified process is the rational unified process (RUP). Other examples are OpenUP and agile unified process.

<span class="mw-page-title-main">V-model (software development)</span> Software development methodology

In software development, the V-model represents a development process that may be considered an extension of the waterfall model, and is an example of the more general V-model. Instead of moving down in a linear way, the process steps are bent upwards after the coding phase, to form the typical V shape. The V-Model demonstrates the relationships between each phase of the development life cycle and its associated phase of testing. The horizontal and vertical axes represent time or project completeness (left-to-right) and level of abstraction, respectively.

<span class="mw-page-title-main">Winston W. Royce</span> American software engineer

Winston Walker Royce (August 15, 1929 – June 7, 1995) was an American computer scientist, director at Lockheed Software Technology Center in Austin, Texas. He was a pioneer in the field of software development, known for his 1970 paper from which the Waterfall model for software development was mistakenly drawn.

Agile Business Intelligence (BI) refers to the use of Agile software development for BI projects to reduce the time it takes for traditional BI to show value to the organization, and to help in quickly adapting to changing business needs. Agile BI enables the BI team and managers to make better business decisions, and to start doing this more quickly.

Agile usability engineering is a method created from a combination of agile software development and usability engineering practices. Agile usability engineering attempts to apply the principles of rapid and iterative development to the field of user interface design.

Evolutionary database design involves incremental improvements to the database schema so that it can be continuously updated with changes, reflecting the customer's requirements. People across the globe work on the same piece of software at the same time hence, there is a need for techniques that allow a smooth evolution of database as the design develops. Such methods utilize automated refactoring and continuous integration so that it supports agile methodologies for software development. These development techniques are applied on systems that are in pre-production stage as well on systems that have already been released. These techniques not only cover relevant changes in the database schema according to customer's changing needs, but also migration of modified data into the database and also customizing the database access code accordingly without changing the data semantics.

References

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