Software development refers to a set of computer science activities dedicated to the process of creating, designing, deploying and supporting software.

Software itself is the set of instructions or programs that tell a computer what to do. It is independent of hardware and makes computers programmable. There are three basic types:

• System software to provide core functions such as operating systems, disk management, utilities, hardware management and other operational necessities.
• Programming software to give programmers tools such as text editors, compilers, linkers, debuggers and other tools to create code.
• Application software (applications or apps) to help users perform tasks. Office productivity suites, data management software, media players and security programs are examples. Applications also refers to web and mobile applications like those used to shop on Amazon.com, socialize with Facebook or post pictures to Instagram.

Software development is primarily conducted by programmers, software engineers and software developers. These roles interact and overlap, and the dynamics between them vary greatly across development departments and communities.

Programmers, or coders, write source code to program computers for specific tasks like merging databases, processing online orders, routing communications, conducting searches or displaying text and graphics. Programmers typically interpret instructions from software developers and engineers and use programming languages like C++ or Java to carry them out.

Software engineers apply engineering principles to build software and systems to solve problems. They use modeling language and other tools to devise solutions that can often be applied to problems in a general way, as opposed to merely solving for a specific instance or client. Software engineering solutions adhere to the scientific method and must work in the real world, as with bridges or elevators. Their responsibility has grown as products have become increasingly more intelligent with the addition of microprocessors, sensors and software. Not only are more products relying on software for market differentiation, but their software development must be coordinated with the product’s mechanical and electrical development work.

Software developers have a less formal role than engineers and can be closely involved with specific project areas — including writing code. At the same time, they drive the overall software development lifecycle — including working across functional teams to transform requirements into features, managing development teams and processes, and conducting software testing and maintenance.

The work of software development isn’t confined to coders or development teams. Professionals such as scientists, device fabricators and hardware makers also create software code even though they are not primarily software developers. Nor is it confined to traditional information technology industries such as software or semiconductor businesses.

An important distinction is custom software development as opposed to commercial software development. Custom software development is the process of designing, creating, deploying and maintaining software for a specific set of users, functions or organizations. In contrast, commercial off-the-shelf software (COTS) is designed for a broad set of requirements, allowing it to be packaged and commercially marketed and distributed.

Developing software typically involves the following steps:

• Selecting a methodology to establish a framework in which the steps of software development are applied. It describes an overall work process or roadmap for the project. Methodologies can include Agile development, DevOps, Rapid Application Development (RAD), Scaled Agile Framework (SAFe), Waterfall and others. (See the glossary.)
• Gathering requirements to understand and document what is required by users and other stakeholders.
• Choosing or building an architecture as the underlying structure within which the software will operate.
• Developing a design around solutions to the problems presented by requirements, often involving process models and storyboards.
• Building a model with a modeling tool that uses a modeling language like SysML or UML to conduct early validation, prototyping and simulation of the design.
• Constructing code in the appropriate programming language. Involves peer and team review to eliminate problems early and produce quality software faster.
• Testing with pre-planned scenarios as part of software design and coding — and conducting performance testing to simulate load testing on the application.
• Managing configuration and defects to understand all the software artifacts (requirements, design, code, test) and build distinct versions of the software. Establish quality assurance priorities and release criteria to address and track defects.
• Deploying the software for use and responding to and resolving user problems.
• Migrating data to the new or updated software from existing applications or data sources if necessary.
• Managing and measuring the project to maintain quality and delivery over the application lifecycle, and to evaluate the development process with models such as the Capability Maturity Model (CMM).

The steps of the software development process fit into application lifecycle management (ALM):

• Requirements analysis and specification
• Design and development
• Testing
• Deployment
• Maintenance and support

Software development process steps can be grouped into the phases of the lifecycle, but the importance of the lifecycle is that it recycles to enable continuous improvement. For example, user issues that surface in the maintenance and support phase can become requirements at the beginning of the next cycle.

Software development is also important because it is pervasive. Software has emerged as a key differentiator in many products — from cars to washing machines to thermostats — with a growing Internet of Things connecting them.

Two examples:

• Soul Machines uses software to create artificial online advisors that improve customer service and efficiency. The advisors have human faces, expressions and voices that react intelligently, empathetically and efficiently to customer questions and needs. They can answer over 40 percent of customer inquiries without human intervention — and they learn from their interactions to improve over time. Using SW to incorporate artificial intelligence (AI) capabilities into the development process, Soul Machines can create and roll out an artificial advisor in about 8 to 12 weeks.
• “This is a race,” says Erik Bak-Mikkelsen. “We have to keep up with what’s happening in the market.” Bak-Mikkelsen is head of cloud operations at car2go. He understands that delivering new features and functions to car2go’s ride-sharing apps and vehicles is key to getting and staying ahead. To do so, car2go moved its development operations to a managed-services cloud and adopted a DevOps development model. The result is accelerated development cycles, faster time to market and the capability to scale for future growth.

Using software development to differentiate brands and gain competitive advantage requires proficiency with the techniques and technologies that can accelerate software deployment, quality and efficacy.

• Artificial intelligence (AI): AI enables software to emulate human decision-making and learning. Neural networks, machine learning, natural language processing and cognitive capabilities present developers and businesses with the opportunity to offer products and services that disrupt marketplaces and leap ahead of the competition.
• Cloud-native development: Cloud-native development is a way of building applications to exploit cloud environments. A cloud-native application consists of discrete, reusable components known as microservices that are designed to integrate into any cloud environment. These microservices act as building blocks and are often packaged in containers. Because of this architecture, cloud-native applications can use cloud environments to improve application performance, flexibility and extensibility.
• Cloud-based development: Just as IT organisations look to the cloud to improve resource management and cut costs, so do software development organizations. In this way, the cloud can be used as a fast, flexible and cost-efficient integrated development environment (IDE) or development Platform as a Service (PaaS). Cloud-based development environments can support coding, design, integration, testing and other development functions. They can also offer access to APIs, microservices, DevOps and other development tools, services and expertise.
• Blockchain: Blockchain is a secure, digitally linked ledger that eliminates cost and vulnerability introduced by parties like banks, regulatory bodies and other intermediaries. It is transforming businesses by freeing capital, accelerating processes, lowering transaction costs and more. Blockchain presents a tremendous opportunity for software development. Developers are working with distributed ledgers and open source Hyperledger technology to change how businesses operate.
• Low code: Forrester defines low code as: “Products and/or cloud services for application development that employ visual, declarative techniques instead of programming and are available to customers at low- or no-cost in money and training …” In short, it’s a development practice that reduces the need for coding and enables non-coders or citizen developers to build or help build applications quickly and at lower cost.
• Analytics: Annual demand for data scientists, data developers, and data engineers will reach nearly 900,000 openings by 2023. The demand signifies how critical it is for companies to gain insight and value from the explosion of data. Accordingly, software developers are integrating advanced analytics capabilities into their applications. Cloud-based services and APIs make it simpler to guide data exploration, automate predictive analytics and create dashboards that deliver new insights and improve decision making.
• Model Based Systems Engineering (MBSE): In MBSE, software modeling languages are used to perform early prototyping, simulation and analysis of software designs for early validation. Building designs in MBSE helps you to analyze and elaborate project requirements and move rapidly from design to implementation.
• Mobile: A key capability for software developers is creating mobile apps with deep connections to data that enriches and elevates user experiences. Forrester has found that “deeply integrating digital/mobile customer data has a strong effect on how customers interact with brands.”