LIS 211 Systems Analysis and Design (O'Leary Computing Essentials

System

A collection of activities and elements organized to accomplish a goal.

1. Organizational growth

2. Mergers and acquisitions

3. New marketing opportunities

4. Revisions in governmental regulations

5. Availability of new technology

Reasons to change information systems

System Analysts

Are computer professionals studying an organization's systems to determine what actions to take and how to use computer technology to assist them.

Computer Systems Analysts

2nd top job classification after Computer Engineer (in terms of salary, prestige and security)

Systems Analysis and Design (Systems Life Cycle)

A six-phase problem-solving procedure for examining and improving information systems.

Preliminary Investigation

Systems Analysis

Systems Design

Systems Development

Systems Implementation

Systems Maintenance

6 phases of the Systems Life Cycle

Preliminary Investigation

Phase where the information problems or needs are identified

Systems Analysis

Phase where the present system is studied in depth. New requirements are specified.

Systems Design

Phase where a new or alternative information system is designed.

Systems Development

Phase where new hardware and software are acquired, developed and tested.

Systems Implementation

Phase where the new information system is installed and adapted to the new system, and people are trained to use it.

Systems Maintenance

In this ongoing phase, the system is periodically evaluated and updated as needed.

Preliminary Investigation

Phase where one will determine the need for a new information system. Requested by an end user or a manager who wants something done that is not presently done.

Defining the problem

Suggesting alternative solutions

Preparing a short report

Three tasks in the Preliminary Investigation stage

True

True or false: The report will help the management decide whether to pursue the project further.

Defining the problem

Task in the Preliminary Investigation phase where one will examine whatever current information system is in use.

Interviewing and making observations

Determine what information is needed, by whom, when, and why is accomplished by...

Large information systems

Survey is done by a systems analyst.

Small information systems

Survey can be done by the end user.

Suggesting alternative systems

Task in the Preliminary Investigation phase where one will suggest some possible plans as alternatives to the present arrangement.

Preparing a short report

Task in the Preliminary Investigation phase where the systems analyst writes a report summarizing the results of the preliminary investigation and suggesting alternative systems.

Systems Analysis

Phase where data is collected about the present system.

Gathering data

Analyzing the data

Documenting systems analysis (Systems analysis report)

Tasks in the Systems Analysis stage

Gathering data

Task in the Systems Analysis phase where the systems analyst/end user doing systems analysis-expands on the data gathered during Phase 1. Add details about how the current system works.

1. Observations and interviews

2. From questionnaires given to people using the system

3. Studying documents that describe the formal lines of authority and standard operating procedures

Data is/may be obtained through...

Organizational chart

Shows levels of management and formal lines of authority. Resembles the hierarchy of three levels of management.

1. Top managers

2. Middle managers

3. Supervisors

Hierarchy of three levels of management

Analyzing the data

Task in the Systems Analysis phase where the idea is to learn how information currently flows and to pinpoint why it isn't flowing appropriately.

Checklists

Top-down Analysis Method

Grid Charts

Decision Tables

Systems Flowcharts

Data Flow Diagrams

Automated Design Tools

List of analysis tools

Checklist

Provides a list of questions about key issues.

False: Checklist

True or False: Grid Charts are helpful in guiding the systems analyst/end user through key issues for the present system.

Top-down Analysis Method

Divides a complex system into components, beginning at the top.

False: Top-level components

True or False: Top-down Analysis Method identifies the bottom-level components of a complex system. Each component is then broken down into smaller and smaller components

Grid Charts

Shows relationship between input and output documents.

Decision Tables

Specifies decision rules and circumstances when specific rules are to be applied.

True

True or False: Decision Tables show the decision rules that apply when certain conditions occur.

Systems Flowcharts

Show the flow of input data to processing and finally to output, or distribution of information

Data Flow Diagrams

Show the data or information flow within the system, organization, or application.

True

True or False: In Data Flow Diagrams, the data is traced from its origin through processing, storage and output.

Automated Design Tools

Software packages that evaluate the hardware and software alternatives according to requirements given by the systems analyst.

Computer-Aided Software Engineering tools

Automated Design Tools are also called...

Computer-Aided Software Engineering

CASE means...

True

True or False: Automated Design Tools or CASE tool relieve the systems analysts of many repetitive tasks

1. Current information system

2. Requirements for a new system

3. Possible development schedule

A Systems analysis report describes:

Designing alternative systems

Selecting the best system

Writing a systems design report

Tasks in the Systems Design stage

Economic feasibility

Technical feasibility

Operational feasibility

Three types of feasibility studies

Economic feasibility

Type of feasibility that asks questions like: "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

Type of feasibility that asks questions like: "Are reliable hardware, software, and training available to make the system work?" "If not, can they be obtained?"

Operational feasibility

Type of feasibility that asks questions like: "Can the system actually be made to operate in the organization, or will people - employees, managers, clients - resist it?"

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?

When selecting the best design, managers must consider these 4 questions

Writing a Systems Design Report

Task in the Systems Design phase: Is prepared for higher management and describes the alternative designs. Presents the costs versus the benefits and outlines the effect of alternative designs on the organization.

False: Usually concludes

True or False: Writing a Systems Design Report usually begins by recommending one of the alternatives.

Acquiring Software

Acquiring Hardware

Testing the New System

Tasks in Systems Development

1. Purchased as off-the-shelf software and possibly modified

2. Custom designed

2 ways to obtain application software

Acquiring Hardware

In the Systems Development stage, this task is concerned with the equipment needed and the places where they are to be installed must be determined.

False: Expensive proposition

True or False: Switching or upgrading equipment can be tremendously cheap proposition

Testing the New System

In the Systems Development stage, this task is concerned with after the software and equipment have been installed, the system should be tested.

True

True or False: Testing may take several months if the new system is complex.

Conversion

Training

Tasks in Systems Implementation

Conversion

Another name for systems implementation

Direct Approach

Parallel Approach

Pilot Approach

Phased Approach

Types of conversion

Direct Approach

Conversion approach where: Abandon the old

Direct Approach

Conversion approach where: Very risky; not recommended

Parallel Approach

Conversion approach where: Run the old and new side by side

Parallel Approach

Conversion approach where: Very low risk; however, very expensive; not generally recommended

Pilot Approach

Conversion approach where: Convert part of organization first

Pilot Approach

Conversion approach where: Less expensive but riskier than parallel conversion; recommended for situations that many people performing similar operations

Phased Approach

Conversion approach where: Implementation gradually

Phased approach

Conversion approach where: Less risky but more expensive than parallel conversion; Recommended for situations with many people performing different operations.

Training

One of the most commonly overlooked activities.

False: is important

True or False: Training people is not as important.

Systems Maintenance

Very important, ongoing activity. Most organizations spend more time and money on this phase than on any of the others.

Systems Audit

Periodic Evaluation

Tasks in Systems Maintenance

Systems Audit

Task in the Systems Maintenance stage where the system's performance is compared to the original design specifications.

True

True or False: Systems Audit will determine whether the new procedures are actually furthering productivity. If they are not, some redesign may be necessary

Periodic Evaluation

Task in the Systems Maintenance stage where after the systems audit, the new information system is further modified, if necessary.

1. Meeting the goals

2. Providing the service they are supposed to

All systems should be evaluated from time to time. This is to determine whether they are:

Prototyping

Rapid Applications Development

Alternative approaches that require much less time:

Prototyping

Means 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.

False: ready

True or False: The systems analyst would revise the prototype until the users felt it was not ready to put into place.

Rapid Applications Development

RAD means

Rapid Applications Development (RAD)

Involves the use of powerful development software, small specialized teams, and highly trained personnel.