1. Explain class stereotypes; include the boundary class, entity class and control class
Class stereotypes is one of three types of extensibility mechanisms in the Unified Modeling Language (UML), other two being tags and constraints. They allow designers to extend the vocabulary of UML in order to create new model elements, derived from existing ones, but that have specific properties that are suitable for a particular problem domain or otherwise specialized usage. For example, when modeling a network you
might need to have symbols for representing routers and hubs. By using stereotyped nodes you can make these things appear as primitive building blocks.
– Boundary objects model interaction between the system and actors (and other systems)
– Entity objects represent information and behaviour in the application domain
– Control objects co-ordinate and control other objects.
2. The four main approaches for requirements determination are interviews, direct observation, and document analysis. An interview is a discussion, involving a combination of open-ended and closed-ended questions that takes place between the systems analyst and another stakeholder such as a user or manager. With direct observation, the systems analyst watches and listens as the user or manager works with an existing system or performs the tasks in his or her job. In documents analysis, the systems analyst studies manuals, organizational policy documents, procedures documents and memos in order to glean information regarding system requirements. There are a variety of factors that influence which approach to use, such as expense, information richness, time commitment, confidentiality, probing, subject involvement, and potential audience. Interviews and direct observation tend to require more time and expense than document analysis, but tend to provide richer information and allow for better probing and follow-up opportunities. Confidentiality is limited with observation and interviews, and tends to be greater with document analysis (although this depends on the nature of the document). With interviews and observation, the time expense and need for subject involvement is so...