LESSON 64
MAINTENANCE PHASE
The Maintenance Phase is the last phase in system development.
Maintenance refers to the changes in the system by fixing or enhancing its
functionality.
System developers are involved in the Maintenance Phase.
System maintenance involves checking, changing and enhancing to improve its performance.
All systems need to be maintained to take care of new requirements that were not discovered previously.
CORRECTIVE MAINTENANCE
Corrective Maintenance is changing maintenance carried out to repair an error in system design.
This maintenance is used when errors are detected and need to be rectified.
For example, in the School Resource System, you need to add the International Standard Book Number (ISBN) field.
PERFECTIVE MAINTENANCE
Perfective Maintenance is a system maintenance performed to improve a
computer program.
Perfective Maintenance is done when the users require changes in the interfaces.
For example, in the School Resource System, you can modify the layout of the Book Form by changing the font colour, type, size and adding "Book Form" title.
PREVENTIVE MAINTENANCE
Preventive Maintenance is a maintenance aimed at the prevention of future breakdowns and failures.
This maintenance is carried out when there is a possibility or risk of failure while operating.
For example, in the School Resource System, you want to assign a password
before a user accesses the database.
Some users may only be allowed to view data in a particular Table.
Some may only be allowed to add records to a Table while others may be given the right to view and modify information.
The use of passwords thus helps to prevent unauthorised access to confidential information.
Preventive Maintenance needs to be done to avoid possible future problems.
EXTENSION : BACKUP A DATABASE
Backup is a process of making copies of data. To backup a database involves the backup of a whole database system.
The backup can be used to restore the original data to prevent data loss caused by virus or power failure.
Backup of database should be done regularly. In this way, you can still access to your backup if anything goes wrong.
Backups should be done on an external medium with a USB memory stick, external hard drive, CD, DVD or server.
DOCUMENTATION PHASE (Lesson 63)
LESSON 63
DOCUMENTATION PHASE
The Documentation Phase is the fifth phase in system development.
Documentation refers to the written materials generated throughout phases of system development.
DOCUMENTATION
Documentation is very important when the system requires changes in the future. Documentation tells new system developers what was done in the program.
It helps to reduce the amount of time a new system developer spends learning about existing programs.
A number of documents are produced during the development of a new computer application.
User Manual
The User Manual helps the user to use the system.
User Manuals are written in simple language rather than technical language.
The User Manual should cover how to run the system, how to enter data, how to modify data and how to save and print reports.
The User Manual should include ways to overcome errors.
Technical Documentation
Technical Documentation is used by system developers as a reference.
Technical Documentation is useful for system improvement.
In Documentation Phase, User Manual and Technical Documentation are found in a folio.
You need to gather all the documents from the system development phases into a folio.
You can compile your Technical Documentation in the form of a hard copy.
Documentation can also be gathered in a soft copy.
All documentation must be ready by the end the system development. The system developers should ensure that all documentation is complete and accurate.
EXTENSION : CREATING A HELP FILE
A Help File is a documentation file that brings together help information of all the database objects in a project.
This file is a guideline for the user when the user needs any help in operating the program.
System developers will create a Help File at the final stage of a project.
For example, system developers can use Help Generator Wizard to create a Help File for School Resource System.
DOCUMENTATION PHASE
The Documentation Phase is the fifth phase in system development.
Documentation refers to the written materials generated throughout phases of system development.
DOCUMENTATION
Documentation is very important when the system requires changes in the future. Documentation tells new system developers what was done in the program.
It helps to reduce the amount of time a new system developer spends learning about existing programs.
A number of documents are produced during the development of a new computer application.
User Manual
The User Manual helps the user to use the system.
User Manuals are written in simple language rather than technical language.
The User Manual should cover how to run the system, how to enter data, how to modify data and how to save and print reports.
The User Manual should include ways to overcome errors.
Technical Documentation
Technical Documentation is used by system developers as a reference.
Technical Documentation is useful for system improvement.
In Documentation Phase, User Manual and Technical Documentation are found in a folio.
You need to gather all the documents from the system development phases into a folio.
You can compile your Technical Documentation in the form of a hard copy.
Documentation can also be gathered in a soft copy.
All documentation must be ready by the end the system development. The system developers should ensure that all documentation is complete and accurate.
EXTENSION : CREATING A HELP FILE
A Help File is a documentation file that brings together help information of all the database objects in a project.
This file is a guideline for the user when the user needs any help in operating the program.
System developers will create a Help File at the final stage of a project.
For example, system developers can use Help Generator Wizard to create a Help File for School Resource System.
TESTING PHASE (Lesson 62)
TESTING PHASE
Testing Phase is the fourth phase of system development. It involves the system developer and user in the Testing Phase.
To ensure the quality of a database, the system developers act as quality controllers and will run tests on it.
The purpose of system testing is to ensure the system runs correctly and is error free.
DATA ENTRY IN TESTING PHASE
Before testing the database, data must be entered into the Tables. Enter data for four Tables : Author, Book, Category and Publisher.
TESTING ON DATABASE OBJECT
You can do the testing to verify that each database object is functioning.
You need to conduct testing to detect any error present.
TESTING ON FUNCTIONALITY OF THE SYSTEM
You can also conduct a test to verify that all systems work together properly.
EXTENSION : DATA VALIDATION
Validation is the process of comparing the data to a set of rules or values to
determine if the data is accurate.
For example, the quantity a user keyed in should be less or equal to 1000. The message will pop up if the quantity is over 1000.
A range check is another example of a validity check.
For example, the salary a user keyed in should be between 900 and 1500. The message will pop up if the salary is over 1500.
By implementing data validation, it minimises data entry errors.
Testing Phase is the fourth phase of system development. It involves the system developer and user in the Testing Phase.
To ensure the quality of a database, the system developers act as quality controllers and will run tests on it.
The purpose of system testing is to ensure the system runs correctly and is error free.
DATA ENTRY IN TESTING PHASE
Before testing the database, data must be entered into the Tables. Enter data for four Tables : Author, Book, Category and Publisher.
TESTING ON DATABASE OBJECT
You can do the testing to verify that each database object is functioning.
You need to conduct testing to detect any error present.
TESTING ON FUNCTIONALITY OF THE SYSTEM
You can also conduct a test to verify that all systems work together properly.
EXTENSION : DATA VALIDATION
Validation is the process of comparing the data to a set of rules or values to
determine if the data is accurate.
For example, the quantity a user keyed in should be less or equal to 1000. The message will pop up if the quantity is over 1000.
A range check is another example of a validity check.
For example, the salary a user keyed in should be between 900 and 1500. The message will pop up if the salary is over 1500.
By implementing data validation, it minimises data entry errors.
IMPLEMENTATION PHASE Lesson 61)
LESSON 61
IMPLEMENTATION PHASE
The Implementation Phase is the third phase of system development.
The Implementation Phase is the phase where a system is created.
CREATING DATABASE
In this phase, a system developer uses database software such as Microsoft Access as the development tool to create a Scholl Resource System.
CREATING TABLES
You can use Design View to create tables to store data. You are to create four tables: Author, Book, Publisher and Category for the School Resource System.
ASSIGNING TABLE RELATIONSHIP
Referential Integrity is a set of rules that ensures relationships between Tables within a database are all valid.
CREATING QUERIES
CREATING FORMS
You can use Forms to perform data entry and retrieve related data.
CREATING REPORTS
You can use Reports to summaries information from the database.You can create new Report using wizard.
You can use Reports to retrieve information from the database using Table or Query.
EXTENSION : TYPES OF RELATIONSHIP
One-To-One
For example, each member has only one address record.
One-To-Many
For example, each book has only one category. Each Category has many books.
One-to-one relationships happen when there is only one record in Library Member to another one record in Member Contact.
One-to-many relationships happen when each record in Book Category has many related records in Book.
In the Implementation Phase, the system developers will convert the technical plan and design plan into a computer program.
IMPLEMENTATION PHASE
The Implementation Phase is the third phase of system development.
The Implementation Phase is the phase where a system is created.
CREATING DATABASE
In this phase, a system developer uses database software such as Microsoft Access as the development tool to create a Scholl Resource System.
CREATING TABLES
You can use Design View to create tables to store data. You are to create four tables: Author, Book, Publisher and Category for the School Resource System.
ASSIGNING TABLE RELATIONSHIP
Referential Integrity is a set of rules that ensures relationships between Tables within a database are all valid.
CREATING QUERIES
CREATING FORMS
You can use Forms to perform data entry and retrieve related data.
CREATING REPORTS
You can use Reports to summaries information from the database.You can create new Report using wizard.
You can use Reports to retrieve information from the database using Table or Query.
EXTENSION : TYPES OF RELATIONSHIP
One-To-One
For example, each member has only one address record.
One-To-Many
For example, each book has only one category. Each Category has many books.
One-to-one relationships happen when there is only one record in Library Member to another one record in Member Contact.
One-to-many relationships happen when each record in Book Category has many related records in Book.
In the Implementation Phase, the system developers will convert the technical plan and design plan into a computer program.
DESIGN PHASE (Lesson 60)
The
Design Phase is the second phase in system development. It refers to the
planning of the system design.
GUIDELINES
FOR DESIGNING A DATABASE:
Choose data
Choose
the neccessary data you need to store in the database. For example, in the
School Resource System, the necessary data are Author, Book, Category and
Publisher.
Ensure table contains the necessary data
In
this School Resource System, there are four Tables involved, namely Author,
Book, Category and Publisher.
From
the analysis, the system developers found out that:
An
author can have one or more books.
A
publisher has one or more books.
A
category has many books.
Determine field
You
need to ensure Tables contain the necessary data.
You
need to determine what fields to include and the suitable data type format for
those fields.
Author
Table consists of AuthorID and AuthorName.
Book
Table consists of BookID, BookTitle and BookPrice.
Category
Table consists of CategoryID and CategoryName.
Publisher
Table consists of PublisherID and PublisherName.
These
are the technical plans we designed during the Design Phase.
In the Design Phase, the system developers will
seek to provide input interface and output interface.
System developers will provide an input interface
where the user can do data entry.
The user can also retrieve information from a
database using an output interface.
ENTITY
RELATIONSHIP DIAGRAM
Entity
Relationship Diagram (ERD) is one of the diagrams that show how Tables are
organised and related to one another.
There
are two symbols used in an Entity Relationship Diagram.
In
the School Resource System, system developers can use the Entity Relationship
Diagram to describe all Tables and their fields.
EXTENSION
: MOCKUP
A
mockup is a sample of the input or output that contains actual data.
A
mockup is needed when handling a big database program so that the system
developer and target user understands the system better.
The system developers show mockups to users for
their approval.
It
is important to involve users during input and output design stages because
users finally will work with those designs.
Users
must give their approval on all inputs and outputs before system developers
proceed with database design. A mockup ensures input and output designs meet
the needs of users.
ANALYSIS PHASE (Lesson 59)
ANALYSIS PHASE OF
SYSTEM DEVELOPMENT
The
Analysis Phase is the first phase of system development.
In this
phase, the system developers would need to define problems faced by target
users.
The target
users will indicate their requirements. They need to give a description of what
a system must do and the main functions of the system.
By doing this,
the system developers can define the purpose of the system. It would help
system developers set the focus of the system.
PROBLEM ANALYSIS
During the
Analysis Phase, the system developers will interview the target users to find
out their needs.
For
example, in the School Resource Centre, the system developers found out that
the target users are currently using the manual system.
They are
facing difficulties in keeping resource materials organised as the volume of
books is increasing.
The target
users require a new system that is a School Resource System to register and
catalogue their books.
By doing
problem analysis, the system developers would have to understand the needs of
the target users.
The new
system should store all book details as in a manual system.
The new
system should be faster, easier to use and have a larger storage.
In the
School Resource System, the system developers need to identify the input,
process and output for the system.
The system
developers identify the input, for example AuthorName, PublisherName,
CategoryName, BookTitle and BookPrice.
The system
developers identify the process for all the system. All new books
purchased
by the School Resource Centre would have all their data keyed into the School
Resource System.
The system
developers identify the output for the system. For example, the books which
have been keyed in will be printed out as document references in the School
Resource Centre.
By doing
this problem analysis, the system developers can come up with the design of the
system.
EXTENSION :
STANDARDISATION
Standardisation
is a set of rules and procedures that system developers require target users to
accept and follow.
For
example, system developers need standardisation for the coding of stock name.
In Analysis Phase, system
developers need to understand the terms used by target users in order to set a
standardisation for input, process and output.
If the
stock code is set to S00001, the target user must follow the standard by using
the prefix S for the rest of the stock code. For example S00002, S00003 and so
on.
Standardisation
is used to help people working on the same development project to produce
consistent results.Without standardisation, the system will not function
correctly. Setting standards
avoids confusion in the whole process of system development.
PHASES OF SYSTEM DEVELOPMENT (Lesson 58)
The system development phase is a series of steps used to develop a database program.
These phases describe the processes that system developers carry out in order to develop a database program.
OVERVIEW OF SYSTEM DEVELOPMENT PHASES
Analysis Phase
During the Analysis Phase, system developers will perform problem analysis by finding out the needs of target users.System developers also identify the input, process and output for the new system.
Design Phase
Based on the needs of target users, the system developers will design an Entity Relationship Diagram (ERD). This phase is known as the Design Phase.
Implementation Phase
Implementation Phase is the phase where system developers create database using database software.
Testing Phase
The system will be tested by the target users in the Testing Phase.If there is any error detected, the system developers will fix the error.
Documentation Phase
System developers will produce the documents for the program during the Documentation Phase.
Maintenance Phase
The system developers continue to provide support during the Maintenance Phase. They monitor the system performance and make changes when needed.
EXTENSION : PRACTICES OF DEVELOPING A NEW
INFORMATION SYSTEM
Some practices of developing a new information system:
Work as a group
When you want to develop an information system, you must work as a group. All group members must work together to complete tasks like data entry and analysis.
Involves many people
Involve as many people as possible in your project. This means that you should not only think of people in your group but also friends and teachers who will use your information system.
Willing to accept changes
Create a culture among yourselves to accept changes. For example, each of you should try changing roles throughout your project so that everyone learns each other’s responsibilities.
You must be willing to accept changes when others give comments or recommendations. Share with others
Tell as many people as you can about what your group is doing. This encourages sharing of ideas and learning from one another.
These phases describe the processes that system developers carry out in order to develop a database program.
OVERVIEW OF SYSTEM DEVELOPMENT PHASES
Analysis Phase
During the Analysis Phase, system developers will perform problem analysis by finding out the needs of target users.System developers also identify the input, process and output for the new system.
Design Phase
Based on the needs of target users, the system developers will design an Entity Relationship Diagram (ERD). This phase is known as the Design Phase.
Implementation Phase
Implementation Phase is the phase where system developers create database using database software.
Testing Phase
The system will be tested by the target users in the Testing Phase.If there is any error detected, the system developers will fix the error.
Documentation Phase
System developers will produce the documents for the program during the Documentation Phase.
Maintenance Phase
The system developers continue to provide support during the Maintenance Phase. They monitor the system performance and make changes when needed.
EXTENSION : PRACTICES OF DEVELOPING A NEW
INFORMATION SYSTEM
Some practices of developing a new information system:
Work as a group
When you want to develop an information system, you must work as a group. All group members must work together to complete tasks like data entry and analysis.
Involves many people
Involve as many people as possible in your project. This means that you should not only think of people in your group but also friends and teachers who will use your information system.
Willing to accept changes
Create a culture among yourselves to accept changes. For example, each of you should try changing roles throughout your project so that everyone learns each other’s responsibilities.
You must be willing to accept changes when others give comments or recommendations. Share with others
Tell as many people as you can about what your group is doing. This encourages sharing of ideas and learning from one another.
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