Chpt 12 Overview

Card Set Information

Chpt 12 Overview
2014-11-17 00:27:21
DiscoveringComputers ShellyCashman
Notecards for CSM Bus 103, from Shelly Cashman's Discovering Computers chapter 12.
Show Answers:

  1. What Is System Development, and What Are the System Development Phases?
    An information system (IS) is hardware, software, data, people, and procedures that work together to produce quality information. System development is a set of activities used to build an information system. System development activities often are grouped into larger categories called phases. This collection of phases sometimes is called the system development life cycle (SDLC). Many SDLCs contain five phases: planning; analysis; design; implementation; and operation, support, and security.
  2. What Are Guidelines for System Development?
    System development should follow three general guidelines: (1) group activities into phases; (2) involve the users, which includes anyone for whom a system is being built; and (3) define standards, which are sets of rules and procedures an organization expects employees to accept and follow.
  3. Why Are Project Management, Feasibility Assessment, Documentation, and Data and Information Gathering Techniques Important?
    Project management is the process of planning, scheduling, and then controlling the activities during system development. The goal of project management is to deliver an acceptable system to the user in an agreed-upon time frame, while maintaining costs. For larger projects, project management activities often are separated between a project manager and a project leader. Some organizations use extreme project management. The project leader identifies the scope of the project, required activities, time estimates, cost estimates, the order of activities, and activities that can take place simultaneously. The project leader records this information in a project plan. Feasibility is a measure of how suitable the development of a system will be to the organization. A systems analyst typically uses four tests to evaluate feasibility of a project: operational feasibility, which measures how well the proposed system will work; schedule feasibility, which measures whether established project deadlines are reasonable; technical feasibility, which measures whether the organization has or can obtain the hardware, software, and people to deliver and then support the system; and economic feasibility, also called cost/benefit feasibility, which measures whether the lifetime benefits of the proposed system will be greater than its lifetime costs. Documentation is the collection and summarization of data and information and includes reports, diagrams, programs, or other deliverables. A project notebook contains all documentation for a single project. To gather data and information, systems analysts and other IT professionals review documentation, observe, survey, interview, participate in joint-application design (JAD) sessions, and research.
  4. What Activities Are Performed in the Planning Phase?
    The planning phase for a project begins when the decision-making body for the organization, called the steering committee, receives a project request. During the planning phase, four major activities are performed: (1) review and approve the project requests, (2) prioritize the project requests, (3) allocate resources such as money, people, and equipment to approved projects, and (4) form a project development team for each approved project.
  5. What Is the Purpose of Activities Performed in the Analysis Phase?
    The analysis phase consists of two major activities: (1) conduct a preliminary investigation, sometimes called the feasibility study, to determine the exact nature of the problem or improvement and decide whether it is worth pursuing, and (2) perform detailed analysis. Detailed analysis involves three major activities: (1) study how the current system works; (2) determine the users’ wants, needs, and requirements; and (3) recommend a solution. Detailed analysis sometimes is called logical design. Most systems analysts use either a process modeling or object modeling approach to analysis and design.
  6. What Are Tools Used in Process Modeling?
    Process modeling, sometimes called structured analysis and design, is an analysis and design technique that describes processes that transform inputs into outputs. Tools used for process modeling include the following. An entity-relationship diagram (ERD) graphically shows the connections among entities in a system. An entity is an object in the system that has data. A data flow diagram (DFD) graphically shows the flow of data in a system. Key elements of a DFD are a data flow, which shows the input or output of data or information; a process, which transforms an input data flow into an output data flow; a data store, which is a holding place for data and information; and a source, which identifies an entity outside the scope of the system. The project dictionary, sometimes called the repository, contains all the documentation and deliverables of a project. Techniques used to enter items in the project dictionary include structured English, a decision table and/or a decision tree, and a data dictionary.
  7. What Are Tools Used in Object Modeling?
    Object modeling, sometimes called object-oriented (OO) analysis and design, combines the data with processes that act on the data into a single unit, called an object. Object modeling can use the same tools as those used in process modeling, but the UML (Unified Modeling Language) has been adopted as a standard notation for object modeling and development. Two common tools in the UML are the use case diagram and the class diagram. A use case diagram graphically shows how actors interact with the information system. An actor is a user or other entity, and the use case is the function that the actor can perform. A class diagram graphically shows classes and one or more lower levels, called subclasses, in a system. Lower levels (subclasses) contain attributes of higher levels (classes) in a concept called inheritance.
  8. What Activities Are Performed in the Design Phase?
    The design phase consists of two major activities: (1) if necessary, acquire hardware and software and (2) develop all of the details of the new or modified information system. Acquiring necessary hardware and software involves identifying technical specifications; soliciting vendor proposals, testing and evaluating vendor proposals, and making a decision. Detailed design includes developing designs for the databases, inputs, outputs, and programs. During detailed design, many systems analysts use a prototype, which is a working model of the proposed system. Computer-aided software engineering (CASE) products are tools designed to support one or more activities of system development
  9. Why Is Program Development Part of System Development?
    During the design phase, an organization can purchase packaged software, which is mass-produced, copyrighted, prewritten software. If suitable packaged software is not available, however, a company may opt for custom software, which is application software developed at the user’s request to match the user’s requirements exactly. Programmers write custom software from the program specification package created during the analysis phase, following an organized set of activities known as the program development life cycle.
  10. What Activities Are Performed in the Implementation Phase?
    The purpose of the implementation phase is to construct, or build, the new or modified system and then deliver it to the users. System developers perform four major activities in this phase: (1) develop programs, (2) install and test the new system, (3) train users, and (4) convert to the new system.
  11. What Activities Are Performed in the Operations, Support, and Security Phase?
    The purpose of the operation, support, and security phase is to provide ongoing assistance for an information system and its users after the system is implemented. The operations, support, and security phase consists of three major activities: (1) perform maintenance activities, (2) monitor system performance, and (3) assess system security. Organizations today often have a chief security officer (CSO) who is responsible for physical security of an organization’s property and people and also is in charge of securing computing resources. The CSO develops a computer security plan, which summarizes in writing all safeguards that protect the organization’s information assets.