Unit 7 Flashcards
Stages of systems life cycle:
1) Analysis of current system.
2) Design.
3) Testing.
4) System implementation.
5) Documentation.
6) Evaluation.
Methods of researching an existing system:
1) Interviews.
2) Observation.
3) Questionnaires.
4) Examination of existing documents.
Advantages of research method: Interviews.
i. Allows analyst to talk to people using the system.
ii. Can find out practical issues.
iii. Follow up questions can be asked.
What is research method: Interviews?
Talking to people who use the system already.
What is research method: Obeservation?
Watching what is going on.
What is research method: Observation?
Watching what is going on.
What is research method: Questionaries?
Questions with a choice of answers.
What is research method: Examination of existing documents?
Viewing already collected information from documents to make a proper analysis.
Advantages of research method: Observation:
i. Gathers real life details in depth.
Advantages of research method: Questionaries:
i. Can be completed online.
ii. Answers are recorded automatically.
iii. Recorded and analyzed by software.
iv. Analyst and worker do not need to be available at the same time.
v. More truthful.
Advantages of research method: Examination of existing documents:
Collection of new document is not needed.
Disadvantages of research method: Interviews:
i. Workers may feel stressed as they are being interrogated.
Disadvantages of research method: Observation.
i. People don’t work normally if they are being watched.
Disadvantages of research method: Questionnaires.
i. People may not take it seriously.
Disadvantages of research method: Examination of existing documents
i. May be difficult for someone from outside to understand.
Technical documentation contents:
1) Purpose of system.
2) Limitations of system.
3) How to install and run system.
4) Program flowchart.
5) Program language and listing.
6) System flowchart.
7) List of variables used.
8) File structure.
9) Hardware and software requirements.
10) Input and output format.
11) Sample and test runs.
12) Validation routines.
Importance of efficiency of system:
The system was made to ensure the tasks of the business are being solved more efficiently and quickly. If the system makes the company or employees take longer to complete the task, that means the system was a failure.
Characteristics of the existing system that will be analyzed:
1) Data input and output.
2) How data is processed.
3) Problems with the system.
Purpose of system specification:
1) The purpose of the system.
2) Data that needs to be input and output.
3) How the data needs to be processed.
4) Performance indicators such as the time it should take for a user to carry out a particular task.
What are the things design should show?
1) File/data structure.
2) Input formats.
3) Output formats.
4) Validation rules.
Importance of validation routines:
Invalid data can cause a system to behave unexpectedly or stop. If the data entered into a system is incorrect, the output will also be wrong.
Factors to change from one system to another:
1) Hardware.
2) Data files.
3) Training.
Explain system change factor: Hardware.
It is possible old hardware might work, but it is unlikely. The business may have to be shut down to install hardware.
Explain system change factor: Data files:
May be necessary to employ data entry staff to make sure data is entered properly.
Explain system change factor:
If they are familiar with a computerized system already, they may not need training
Training methods for system change:
a. Using a tutor.
b. Put all the lessons in company intranet for employees to see in their own time.
Advantages of phased implementation:
1) No implementation problems.
2) Lesson learnt from early implementation makes it easier to implement later stages.
3) Allows users to adjust to new system gradually
4) Staff training can be done in different stages.
Disadvantages of phased implementation:
1) May be confusing.
2) Data produced by old system may not be compatible.
3) Expensive as two systems run together.
Contents of user document.
1) Purpose of system.
2) Limitations of system.
3) Hardware and software requirements.
4) How to install and run system.
5) Error handling.
6) How to save a file.
7) How to print data.
8) How to access, edit and delete data.
9) Input and output formats.
10) Sample/test runs.
11) Frequently asked questions.
12) Glossary of terms.
Systems life cycle:
Series of stages that are worked through during the development of a new IT system or to improve a new one.
Analysis:
Detailed examination of something for a specific purpose.
Questionnaire:
Questions with a choice of answers to carry out a survey.
Documentation:
Written or printed information like a presentation, spreadsheet, report, database.
Requirement specification:
A document listing to all the functions the system is expected to do.
System specification:
List of all the software and hardware required by the new system.
Design:
Process of defining the elements of a system.
File/data structure:
The way in which the different data items will be stored.
Input format:
How data will be entered into the system.
Output format:
How the results of processing a data will be presented.
Validation rules:
Routines to check if data entered by user meets specific requirements.
Top-down design:
Decomposition of a system into smaller parts in order to comprehend its compositional sub-systems.
Bottom-up design:
Smallest sub-systems are designed first then combined into progressively larger units.
Data structure:
A way of sorting and managing data.
Record:
Consists of all the field about an individual instance of an entity in a database.
Entity:
A thing recognized as being capable of an independent existence which can be identified uniquely.
Field:
The item of information about an entity.
Table:
A collection of rows and columns forming cells that are used to store data in a structured manner.
Data capture form:
A document used for capturing data.
Transcription:
The transfer of data from one medium to another.
Database queries:
Searches made on the data held in a database to find one with a particular specification.
Valid:
Data that has passed validation test.
Validation routines:
Routines to check that the data entered meets the specified requirements.
Range check:
A validation rule to ensure the data is between a minimum and maximum value.
Character check:
Validation rule to ensure that only certain characteristics are entered.
Length check:
Check which ensures that the data entered is no longer than a specified maximum number of characters.
Type check:
A validation rule to ensure that the correct data type has been entered.