IPO charts
An IPO chart records the input, process, and output of a process, or
program module. It is commonly used when designing spreadsheet formulas, calculated fields in databases, and algorithms in programming.
A simple example is to calculate someone's age. Work backwards, starting with deciding what the output should be (Age)
| INPUT |
PROCESSING |
OUTPUT |
|
|
|
Age
|
Now ask what data is needed to generate this output (date of birth, current date)
| INPUT |
PROCESSING |
OUTPUT |
Date of birth
Current date
|
|
Age
|
Finally, work out the algorithm (calculation strategy) to get the output from the input: in this case, find the number of days between the date of birth and the current date, divide by 365.25 to convert it to years.
| INPUT |
PROCESSING |
OUTPUT |
Date of birth
Current date
|
(Current Date - Date of Birth) / 365.25
|
Age
|
Another more complex example...
|
