IT Systems in Organizations (IB)

What are all the IT personnel?

• Information system (IS) managers,

• Support staff

• Network managers

• Database administrator

• Chief information officers (CIO)

What are the development personnel?

• Programmers

• System analysts

• Business analysts

• Project managers

What is the basic structure of system development?

1. Feasibility Study

2. System Analysis

3. System Design

4. System Development and System Testing

5. System Implementation

6. System Evaluation and Maintenance

What is done during the Feasibility Study?

a) Conduct preliminary analysis – includes stating objectives, defining nature and scope of the problem.

b) Propose alternative solution- includes making decisions such as leaving the system alone, making it more efficient, or build a new system

c) Description of cost and benefits of each solution.

d) Submit a preliminary plan with recommendations.

What is done during the System Analysis?

a) Gathering data using tools of written documents, interviews, questionnaires, observations, and sampling.

b) Analyze the data, using data flow diagrams, systems flowcharts, connectivity diagrams , grid charts and decision tables

c) Write a report.

What are the classic fact finding methods?

• Conduct interviews

• Carry out questionnaires

• Study existing documents

• Search the literature for other solutions to the same problem.

• Observe people working with the existing system

What are the three parts of System Design?

Preliminary Design, Detailed Design, Write a Report

What are the three estimates PERT requires?

• Most likely time

• Optimistic time

  • Pessimistic time

What are the validation methods?

a) length checks

b) type checks

c) range checks

d) Presence check

e) check digit test

What are the two stages of System Testing?

a) Unit Testing: Here the individual parts of the program are tested using test (made up) data. Normally different sections (modules) are tested separately.

b) System Testing: Here the parts of the system are linked together and test data used to see if the parts work together. At this point actual firm’s data nay be used

What are the four approaches to System Implementation?

a) Direct approach: means the user simply stops using the old system and starts using the new system.

b) Parallel approach: means the old and new systems are operated side by side until the new system has shown it is reliable, at which time the old system is discontinued.

c) Phased approach: means that parts of the new system are phased in separately.

d) Pilot approach: means that the entire system is tried out but only by some users.

What is SSADM?

SSADM (Structured Systems Analysis and Design Methodology) is a methodology (Def. a system of ways of doing things especially regular and orderly procedures), used in the analysis and design stages of systems development. SSADM does not cover SITP issues or the construction, testing and implementation of software.

What are the major tools of SSADM?

• Logical Data Modelling

• Data Flow Modelling

• Entity Event Modelling

What are the two main verification methods in use?

• Visual verification (or proof-reading) which means... (can you guess?)

• Double entry verification which involves having the data from the source document entered twice as a check. Typically the application will lock the keyboard and give an audible warning so that the data entry person can check carefully.

Why is validation important?

Data entered into the computer can be unreasonable, a data entry person in a medical clinic can easily mistype a person’s weight, say or the number of cigarettes they smoke per day. This type of error is not caught by verification since the data may have been written down wrongly in the first place.