Testing and Development
Once the system has been created, it needs to be thoroughly tested.
A test plan is usually written whilst the system is being developed. The test plan will contain details of every single thing that needs to be tested.
A test plan is usually written whilst the system is being developed. The test plan will contain details of every single thing that needs to be tested.
For example:
- Does the system open
and close properly?
- Can data be entered?
- Can data be saved?
- Can reports be printed?
- When you do
something wrong, does an error message appear?
- Is invalid data
rejected? E.g. if you are not allowed to enter an amount above £1,000 on
the system then a value of 1,001 should not be accepted (i.e. does the validation
work?)
Test plans are very
detailed, and contain many tests. Each test is specified very precisely.
A typical test would contain:
A typical test would contain:
- Details of what
is being tested
- The test data to
use
- What is expected
to happen when the test is performed
When choosing what data to use to test a system, you need to think
about why we are testing the system: to see if it works, and to check it
doesn't break.
To do this, we use three types of test data...
To do this, we use three types of test data...
Normal Data Values
This is data that would normally be entered into the system.
The system should accept it, process it, and we can then check the results that are output to make sure they are correct.
The system should accept it, process it, and we can then check the results that are output to make sure they are correct.
Extreme Data Values
Extreme value are still normal data.
However, the values are chosen to be at the absolute limits of the normal range.
Extreme values are used in testing to make sure that all normal values will be accepted and processed correctly.
However, the values are chosen to be at the absolute limits of the normal range.
Extreme values are used in testing to make sure that all normal values will be accepted and processed correctly.
This is data that should not normally be accepted by the system -
the values are invalid.
The system should reject any abnormal values.
Abnormal values are used in testing to make sure that invalid data does not break the system.
The system should reject any abnormal values.
Abnormal values are used in testing to make sure that invalid data does not break the system.
When
is the System Tested?
Testing is normally done in two stages:)
The first phase of testing is done by the designers and engineers who created the system, usually before the system is delivered to the customer.
The test data that is used in this first phase is similar to data that would be used by the actual customer.
The second phase of testing is done after the system has been delivered and installed with the customer.
The data used in the second phase is usually 'live' data - data that is actually part of the customer's business / organisation.
The first phase of testing is done by the designers and engineers who created the system, usually before the system is delivered to the customer.
The test data that is used in this first phase is similar to data that would be used by the actual customer.
The second phase of testing is done after the system has been delivered and installed with the customer.
The data used in the second phase is usually 'live' data - data that is actually part of the customer's business / organisation.
What
Happens if the System Fails Some Tests?
The whole point of testing is to try and find areas that don't work
as they should, or areas that can be improved.
If any failures are found, the systems analyst goes back and does some further research, analysis and design to fix these areas.
If any failures are found, the systems analyst goes back and does some further research, analysis and design to fix these areas.