ENUM: SYSTEM ANALYSIS

5 reasons to change information systems

• Organizational growth

• Mergers and acquisitions

• New marketing opportunities

• Revisions in governmental regulations

• Availability of new technology 

6 systems life cycle

1. Preliminary investigation

2. Systems analysis

3. Systems design

4. Systems development

5. Systems implementation

6. Systems maintenance 

systems analysts/end user is concerned with three tasks

1. Briefly defining the problem

2. Suggesting alternative solutions

3. Preparing a short report

hierarchy of 3 levels of management

• Top managers

• Middle managers

• supervisors

4 cycle of preliminary investigation

1. problem

2. alternatives

3. report

4. analysis

4 cycle of systems analysis

1. gather

2. analyze

3. report

4. design

7 analysis tools

• Checklists

• Top-down Analysis Method

• Grid Charts

• Decision Tables

• Systems Flowcharts

• Data Flow Diagrams

• Automated Design Tools

6 examples of systems flow chart symbol

1. manual data

2. process

3. decision

4. document

5. data

6. internal storage

4 data flow diagram symbols

1. entities

2. process

3. file

4. data flow

3 tasks in systems design

• Designing alternative systems

• Selecting the best system

• Writing a systems design report

3 feasibilities in designing alternative systems

• Economic feasibility

• Technical feasibility

• Operational feasibility

3 steps systems development

• Acquiring software

• Acquiring hardware

• Testing the new system

2 ways to obtain application software

• Purchased as off-the-shelf software and possibly modified

• Custom designed

testing the new system (4)

• After the software and equipment have been installed, the system should be tested.

• Sample data is fed into the system. 

• The processed information is then evaluated to see whether results are correct.

• Testing may take several months if the new system is complex.

4 types of conversion

• Direct Approach

• Parallel Approach

• Pilot Approach

• Phased Approach

2 parts of system maintenance

• Systems Audit

• Periodic Evaluation

2 alternative approaches that require much less time

• Prototyping

• Rapid Applications Development