IPO charts

A problem can be broken down into 4 components:

1. Input – any data that is needed to solve the problem

2. Processing – the task that will be carried out to solve the problem

3. Output – the end result of the problem

4. Storage – variable are used to store data/values to perform calculation

The IPO (Input, Processing & Output) chart can be used to analyse a problem. This is a table with three columns, which represent three components: input, output and processing. Storage component is not shown.

Follow these 5 steps to complete an IPO Chart:

1. Write the input (what is needed from the person using the algorithm).
2. Write the output (the end result that is stated in the problem).
3. In the processing column write “get” and anything that is under the input column. If nothing is under the input column, leave out this step.
4. Ask yourself the following question. “What do I have to do with the inputs in order to produce the desired output?” Then write down what should be done.
5. Write “display” and anything under the Output column.

E.g. A program is required to read three numbers, calculate and print their total.

Three numbers are needed so write “3 numbers” under INPUT

The question asks for the total to be printed so Sum or Total can be used.

• Write down the word that is followed by 3 numbers.
• Write what should be done to produce the total which is “Calculate the total”
• Write down the word display followed by total.