Software development

Software development is the process of computer programming, documenting, testing, and bug fixing involved in creating and maintaining applications and frameworks resulting in a software product. Software development is a process of writing and maintaining the source code, but in a broader sense it includes all that is involved between the conception of the desired software through to the final manifestation of the software, sometimes in a planned and structured process. Therefore, software development may include research, new development, prototyping, modification, reuse, re-engineering, maintenance, or any other activities that result in software products.Software can be developed for a variety of purposes, the three most common being to meet specific needs of a specific client/business (the case with custom software), to meet a perceived need of some set of potential users (the case with commercial and open source software), or for personal use (e.g. a scientist may write software to automate a mundane task). Embedded software development, that is, the development of embedded software such as used for controlling consumer products, requires the development process to be integrated with the development of the controlled physical product. System software underlies applications and the programming process itself, and is often developed separately. Most methodologies some combination of the following stages of software development:

1. Identification of required software
2. Analyzing the problem
3. Market research
4. Software design
5. Programming Implementation (coding) of the software
6. Testing the software
7. Maintenance and bug fixing

Software development activities

1. Identification of need
The sources of ideas for software products are legion. These ideas can come from market research including the demographics of potential new customers, existing customers, sales prospects who rejected the product, other internal software development staff, or a creative third party. Ideas for software products are usually first evaluated by marketing personnel for economic feasibility, for fit with existing channels distribution, for possible effects on existing product lines, required features, and for fit with the company’s marketing objectives. In a marketing evaluation phase, the cost and time assumptions become evaluated. A decision is reached early in the first phase as to whether, based on the more detailed information generated by the marketing and development staff, the project should be pursued further. In the book “Great Software Debates”, Alan M. Davis states in the chapter “Requirements”, subchapter “The Missing Piece of Software Development” Students of engineering learn engineering and are rarely exposed to finance or marketing. Students of marketing learn marketing and are rarely exposed to finance or engineering. Most of us become specialists in just one area. To complicate matters, few of us meet interdisciplinary people in the workforce, so there are few roles to mimic. Yet, software product planning is critical to the development success and absolutely requires knowledge of multiple disciplines. Because software development may involve compromising or going beyond what is required by the client, a software development project may stray into less technical concerns such as human resources, risk management, intellectual property, budgeting, crisis management, etc. These processes may also cause the role of business development to overlap with software development.

2. Planning Planning is an objective of each and every activity, where we want to discover things that belong to the project. An important task in creating a software program is extracting the requirements or requirements analysis. Customers typically have an abstract idea of what they want as an end result, but do not know what software should do. Skilled and experienced software engineers recognize incomplete, ambiguous, or even contradictory requirements at this point. Frequently demonstrating live code may help reduce the risk that the requirements are incorrect. Once the general requirements are gathered from the client, an analysis of the scope of the development should be determined and clearly stated. This is often called a scope document. Certain functionality may be out of scope of the project as a function of cost or as a result of unclear requirements at the start of development. If the development is done externally, this document can be considered a legal document so that if there are ever disputes, any ambiguity of what was promised to the client can be clarified.

3. Designing Once the requirements are established, the design of the software can be established in a software design document. This involves a preliminary, or high-level design of the main modules with an overall picture (such as a block diagram) of how the parts fit together. The language, operating system, and hardware components should all be known at this time. Then a detailed or low-level design is created, perhaps with prototyping as proof-of-concept or to firm up requirements.

4. Implementation, testing and documenting Implementation is the part of the process where software engineers actually program the code for the project.Software testing is an integral and important phase of the software development process. This part of the process ensures that defects are recognized as soon as possible. In some processes, generally known as test-driven development, tests may be developed just before implementation and serve as a guide for the implementation’s correctness. Documenting the internal design of software for the purpose of future maintenance and enhancement is done throughout development. This may also include the writing of an API, be it external or internal. The software engineering process chosen by the developing team will determine how much internal documentation (if any) is necessary. Plan-driven models (e.g., Waterfall) generally produce more documentation than Agile models.

5. Deployment and maintenance Deployment starts directly after the code is appropriately tested, approved for release, and sold or otherwise distributed into a production environment. This may involve installation, customization (such as by setting parameters to the customer’s values), testing, and possibly an extended period of evaluation. Software training and support is important, as software is only effective if it is used correctly. Maintaining and enhancing software to cope with newly discovered faults or requirements can take substantial time and effort, as missed requirements may force redesign of the software.

Types of Software Development

1. Applications Development Designing and coding software which is used by humans to solve a particular practical problem. For example, the developers in a company’s IT department may write a tool designed to help the sales staff manage sales data. The term “applications development” usually implies non-Web based software. The most common languages used by applications developers are Java, Visual Basic, VB.NET, and C#.

2. Systems Development Designing and coding software which works behind the scenes. For example, several thousand engineers who work at Microsoft developing the Windows operating system are systems developers. A subcategory is API development, where engineers write code which is intended to be used by other developers who are writing application programs. The most common languages used by systems developers are C and C++.

3. Web Development Designing and coding applications which are housed in a Web browser such as Internet Explorer, Netscape Navigator, or Firefox. For example, an online shopping system such as is an example of Web development. The most common languages used by Web developers are HTML, VBScript, PHP, and JavaScript, VB.NET, and C #.

4. Embedded Systems Development Designing and coding software which works on non-computer devices. For example, engineers who write programs which control the guidance systems of military devices are writing embedded systems code. The most common languages used by embedded systems developers are Assembly Languages, C, and special one-of-a-kind languages.

5. Scientific Development Designing and coding software which is primarily numerical. This type of programming is much less common than it used to be. The most common languages used by scientific programmers are C and C++.

6. Test Automation Designing and coding software which tests other software. Microsoft employs thousands of these engineers who have job title Software Design Engineer in Test, or SDET for short. The most common programming languages used by test engineers are Perl, Visual Basic, VB.NET, and C#.