Chapter 13 Flashcards
System Analysis and Design Phases
A collection of activities and elements organized to accomplish a goal
System
A computer professionals studying an organization’s systems to determine what actions to take and how to use computer technology to assist them.
Systems Analysts
Give 5 reasons to change information systems
- Organizational growth
- Mergers and acquisitions
- New marketing opportunities
- Revisions in governmental regulations
- Availability of new technology
What are the 6 phases of System analysis and design?
- Preliminary investigation
- System analysis
- System design
- System development
- System implementation
- System maintenance
Explain the given Phase of System analysis and design.
Phase 1
Prelimenary Investigation
determines the need for new information requested by an end user or a manager who wants something done that is not presently done. The System analysts/End user is concerned with three tasks:
1. Briefly defining the problem - examines whatever the current information system is in use by determining the information needed, through whom, when, and why accomplished by interviewing and making observation.
2. Suggesting alternative solutions - suggest some possible plans as alternatives to the present arrangement
3. Preparing a short report - System Analyst writes a report summarizing the results of the preliminary investigation and suggesting alternative systems.
Explain the given Phase of System analysis and design.
Phase 2
System Analysis data is collected about the current system is then analyzed while determining the requirements for a new system. It is concerned with gathering then analyzing the data. And can be completed by documenting the analysis in a report.
What is the Proccess of Phase 2?
Gathering Data - the system analyst/end user doing analysis-expands on the data gathered during Phase 1. It add details about how the current system works. Data may be obtained through observation and interviews from questionniares given to people using the system. And studying documents that describe the formal lines of authority and standard operating procedures.
Anaylzing the Data - the idea is to learn how information currently flows and to pinpoint why it isn’t flowing appropriately. Applies logic to exisiting arrangement to see how workable it is.
Report
Organizational chart consists of?
- Top-level manager
- Middle-level manager
- Supervisor
List the 7 Analysis Tools and explain how it works.
- Checklist - a list of questions of key issues for the present system for system analyst/end user.
- Top-down Analysis Method - a complex system, component is broken down into smaller and smaller components to easier analyze and deal with.
- **Grid Charts **- shows the relationship between input and output documents.
- Decision Tables - shows the decision rules that apply when certain conditions occur
- System Flowcharts - shows the flow of input data to processing and finally to output, or distribution of information.
- Data Flow Diagrams - shows the data or information flow within the system traced from its origin through processing, storage, and output.
- Automated Design Tool - software packages alternatives according to requirements given by the system analyst also called as Computer Aided Software Engineer (CASE)
Explain the given Phase of System analysis and design.
Phase 3
System Design consists of three tasks:
1. Designing alternative systems - determining the feasibility of the system. Economic feasibility; Will the cost of the new system by the benefits it promises? How long will it take for the new system to pay for itself?. Technical feasibility; Are reliable hardware, software, and training available to make the system work? If not, can they be obtained? . Operational feasibility; Can the system actually be made to operate in the organization, or will people - employees, managers, clients - resist it?.
2. Selecting the best system - managers should consider these four quesitons: 1. Will the system fit in with the organization’s overall information system? 2. Will the system be flexible enough so it can be modified in the future? 3. Can it be made secure against unauthorized use? 4. Are the benefits worth the costs?
3. Writing a system design report - prepared for the higher management and describes the alternative designs. Presents the costs versus the benefits and outlines the effect of alternative designs on the organization. And usually concludes by recommending one of the alternatives.
Explain the given Phase of System analysis and design.
Phase 4
System Development - there are 3 steps:
1. Acquiring software
2. Acquiring hardware
3. Testing the new system
Two ways to obtain application software
- Purchased as off-the-shelf
- Custom designed
Another name for Phase 5
Conversion
Explain the given Phase of System analysis and design.
Phase 5
System Implementation - new information system is installed and adapted to the new system, and people are trained to use it.
Types of Conversion and explain how it works
- Direct Approach - Abandon the old, very risky procedure; not recommended.
- Paralled Approach - Run old and new side by side, very low risk; however, very expensive; not generally recommended.
- Pilot Approach - Convert part of organization first, less expensive but riskier than parallel conversion, recommended for situations that many people performing similar operations.
- Phased Approach - Implement gradually, less risky but more expensive than parallel conversion; recommended for situations with many people performing different operations.
One of the most commonly overlooked activities.
Training
Explain the given Phase of System analysis and design.
Phase 6
System Maintenance - a very important, ongoing activity. Most organization spend more time and money on this phase than on any of the others.
Two parts of Phase 6 and explain how it works
- Systems Audit - the system’s performance is compared to the original design specifications. To determine whether the new procedures are actually furthering productivity. If they are not, some redesign may be necessary.
- Periodic Evaluation - After the system audit, the new information system is further modified, if necessary. All systems should be evaluated from time to time to determine whether the are meeting the goals or providing the service they are supposed to.
Alternative Approaches that require much less time
- Prototyping - means of building a model or prototype that can be modified before the actual system is installed. Users would try it out and provide feedback to the systems analyst. The systems analyst would revise the prototype until the user felt it was ready to put into place.
- Rapid Application Development (RAD) - Infolves the use of powerful development software, small specialized teams, and highly trained personnel.
