An application is a program or group of programs designed
for end users. Applications are complete systems that perform specific tasks.
The task is defined by the user.
Goal
The goal of an application is to provide information and
help users to make decisions. Applications serve
two primary functions. They are,
· They establish
and control the user interface.
· They ensure data
integrity.
4.1.1.
User Interface
A user interface is the system by which people (users)
interact with a machine.
The user interface
includes hardware (physical) and software (logical) components. User interfaces
exist for various systems, and provide a means of:
· Input, allowing the
users to manipulate a system
· Output, allowing
the system to indicate the effects of the users' manipulation
A good user interface provides a "user-friendly"
experience, allowing the user to interact with the software or hardware in a
natural and intuitive way.
The
basic concept of improving the user interface is that the application should
reflect the way the user works.
A primary
purpose of an application is to integrate the input forms and reports. Users
should not have to go searching for input forms and reports. They should be
available at the click of a mouse.
Example: If
users customarily print order forms when they are entered, the order-entry form
should have a button to print the corresponding report.
4.1.2.
Ensure Data Integrity
Data
integrity means reliability and accuracy of data. Data integrity is a
fundamental component of information security. A key purpose of applications is
to ensure data integrity.
Example: To maintain data integrity
numeric columns/cells should not accept alphabetic data.
The standard features
to ensure data integrity are,
Data validation
Data validation is the process of
ensuring that a program operates on clean, correct and useful data.
Example
Price
field should always be greater than 0.
Automatic computations
Application should also be used to automatically perform
all computations.
Example
Computation
of sales tax automatically. These business rules are generally written as code
within the forms.
Verification of totals
After computation and storing totals in a database, we
need to write additional code that verifies and corrects the totals.
Example
Quantity
on Hand (QOH) is updated when an item is sold or purchased. A separate program
is required to validate the current totals by examining all sales and
purchases.
Control of user access
An application should have the power of control by
accessing from the user.
Transaction integrity
Transaction processing is used to maintain database
integrity by ensuring that set of SQL operations execute completely or not at all.
The degree to which a
transaction flowing through a network reaches its intended destination without
impairment of its function, content or meaning.
Backup and recovery
Backup and recovery refer to the strategies and procedures
involved in protecting the database against data loss and reconstructing the
data in case of such data loss.
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