We could discuss here such tools as Gantt and PERT charts but they are not included in the syllabus.

However, you might well find them useful to track progress in your dossier.

Testing
There are several different methods of system testing. It may sometimes seem to us that software companies don't always pay as much attention to this aspect as we would wish.  However, it is worth bearing in mind that applications packages typically run to several hundred thousand lines of code and are therefore quite complex.

We can distinguish two types of testing; functional testing and data testing. 

Functional testing involves describing systematically what is supposed to happen when buttons are pressed on an event driven interface or menu choices are selected. If an choice is made to add a record, does the program go to the "add records module"?

Test data should be developed at the design stage of the dossier when the pseudocode has been completed in detail.

Suppose that there is a simple program that accepts a person's percentage in an exam and give an output that they have passed if the percentage is greater than or equal to fifty or otherwise prints a fail message; this can be tested with:

Normal Data such as 23 or 56 will check to see if the pass and fail messages are properly delivered. Data at the Limits should also be checked, for example 0, 49, 50, 100 are all examples of normal data at the limits as defined by our problem description.

Extreme Data will be outside the normal limits, -1, 104, 122 are examples. The user may not type in such data because they're dumb, it's easy to hit a key twice by mistake.

Abnormal Data will be the type of input data we really didn't except (in this case it could be data that looks like a string and not an integer). A user may enter "three" which seems unlikely but they could also hit the spacebar by mistake and enter "3 5" for example.

Thus a test plan for this program might be made up as follows:

Notice that columns have been included to describe what happens when the actual testing is done - the process of detecting, diagnosing and correcting errors in a program is known as debugging . 

related: [ systems home | Systems Flow Charts | Fair Trade Scenario ]

[ previous: design | next: operation ]

Implementation is sometimes used as a term to describe the installation of the system.

Here, we take it mean the actual building of the system, given the design.

Thus, this section is really concerned with implementing the project plan . Most plals include a timeline showing milestones which need to be achieved.

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