- Rate Projections Functions Walkthrough
- Accruals and Cash
- Repeating Formulae
- Range Names and References
- Optional Parameters
- Using PmtsPerYear
- Modelling Seasonality
- Calculating Interest
- Using Business Functions in VBA (Visual Basic for Applications)
- Array Functions
- Volatility
- Annual Equivalent Rates
- Array Function
- Auto Multi Functions
- Variable Plurality
- GoalSeek

**Maintainability**. It is much easier to maintain and debug, owing to the fact that that if you"ve inspected one cell in a row or column to see what it is doing, you"ve effectively inspected them all. One-off "kludges" in particular cells can lead to horrible bugs that take a long time to find. It is harder to write repeating formulas (especially without Business Functions) but it is widely accepted to be better.**Timebase Change**. If the formula is the same, you can generalise it to cope with the time base changing. For example, you may want to change the start date of a model, or run it quarterly instead of annually. This is where Business Functions really makes the job easier, because it expressly permits the length of the time period to be specified when doing projections. So when using a projections function, only the Time and Base should change within a row or column - the other variables in the function should be constant, either input as numbers, as absolute (dollared) references, or best still as Range Names.**This is one of the real advantages of BF**.

## Repeating Formulae | |

Why its best to use the same formula across a projections"s range | |

The projections categories of Business Functions are intended to work with a constant repeating formula across a range of times (timebase). It is much better to copy the same formula over a time range, even if you are not using Business Functions and just using standard Excel functions, for reasons of:A more sophisticated way of have a repeating formula which Business Functions supports is to use Array Functions. Many BF functions in the projections category are "arrayable" which means you only have one formula across a range of cells, and that one formula returns an array. This is called an Array Function. |