Name activities in software development covered by various methodologies. Can you explain why more than one methodology is needed in developing a piece of software?

What will be an ideal response?

A methodology can cover widely differing areas of development process, from high-level strategic and organizational problem solving to the detail of implementing a small computer system. Software development consists of a wide spectrum of activities that individual methodologies cover selectively and from different viewpoints.
• Requirements Gathering. Determines the requirements that the product must address: the problems that it must solve, desires that it must satisfy, or opportunities of which it must take advantage.
• Feasibility Study. Determines whether it is possible technically, economically, legally, or organizationally to build a certain software. If the software is a commercial product, it also evaluates the viability of the product in the marketplace.
• Domain Analysis. Discovers the meaning of requirements within the context, concepts within the domain that are related to the problem and which can affect the solution, and possibly the consequences of the solution on the problem domain.
• Analysis. Analyzes the requirements to build a conceptual model of the solution (the product). Such a model represents what the solution must do, without identifying how.
• Design. Transforms the "what" into "how." Design itself consists of several distinct activities, the most important of which are: logical design, which represents the solution without reference to a specific technology; physical design, which maps the logical modeling to specific technologies; and architectural design, which determines the high-level structure of the product.
• Implementation. Turns the blueprints of design into an actual product. Programming is usually the most important component of this activity, but it is not the only one.
• Testing and Quality Control. Verifies that the product functions according to specifications and does not produce unacceptable consequences.
• Deployment and Training. Depending on whether the software is in-house or commercial, this activity consists of ensuring the correct installation on the target platform (without breaking other things), user training, creating help files and user manuals, setting up Web sites to guide users, packaging, etc.
• Maintenance. Consists of solving problems that may emerge after the deployment of the software due to faulty requirements, insufficient analysis, defective design, or changes in the environment, whether in the business context or in the technological framework.