Application Programming

Application Programming

Application software is usually created by systems analysts and computer programmers. The system analyst studies the particular requirements and objectives of the potential users and decides what the software should do. The programmers then write the detailed programs based on these guidelines, which are often a combination of databases and algorithms. Databases consist of the information that the program processes. Algorithms are the sequences of steps that the program follows to process this intormation. For example, a program to calculate the wages of a company's employees would require:

• a database: details of each employee, number of hours worked, rate of pay, etc.

• algorithms: instructions on how to calculate total pay, tax, social security payments, etc

How application software is written

Preparation begins with a complete description of the job that the computer has to perform. This job description is written after detailed consultation with the people for whom the program is being prepared, such as office managers or engineers. It defines what input data is needed, what computing must be done, and what the output should be. The job description is then used to prepare diagrams, called 'flowcharts', that show in graphic form all the steps needed to complete the various tasks. From the flowchart it is possible ( see how all the various parts of the job fit together systematically. The diagram indicates the logical order of the computer's actions and how the data flows from one step to the next. Based on this masterplan, the program instructions are then coded in a particular programming language. After the program is written, it is tested to see if it works according to the specifications (called 'alpha testing' ) and to eliminate any programming mistakes, known as 'bugs'. This debugging stage is often the most difficult in the whole process since problems in design and logic can be very hard to identify in large complex programs. The program is then given to the users for "beta testing". The users put the program to work under real-life conditions to see whether it really can carry out its task correctly. Further modifications may be needed before it is given final approval.