Back to the Future, Part II

Introduction

Most financial models are based on the fiscal year, rather than aligning with the calendar year.

In many countries, these two calendars align, but in some it does not. In Australia, for instance (my home country), we have a Jul – Jun financial year, and both New Zealand and Japan have their own, too.

Propel Planning, Flow’s budgeting and planning application, always supported the idea of changing the starting month of the fiscal year, but we made some recent improvements which led to a better date lookup cube.

I thought I’d spend some time discussing it and provide a download link for those that are interested.

What was wrong with the old one?

Admittedly, there was not much wrong with the original date lookup cube, and it could still be used for most purposes.

However, there was often a necessity to map from Fiscal Year to Calendar Year and back again to do simple lookups, and we decided we it was worth finding a more efficient way to do this since it’s so core to the Propel Planning system.

To be honest, the former date lookup cube was something I built years ago, for us in consulting where the fiscal year period would be known well in advance of starting the job. And since I started working abroad, I don’t think I ever had a single implementation where the fiscal year was not aligned with the calendar year, and never really had to consider it.

However, Propel Planning is a dynamic, generic budgeting and planning system that can be sold world-wide, so it was time to face the music!

The Approach

A fresh look

I took a different approach this time, in several ways.

Instead of creating all the data in Excel and importing it into a TM1 cube, I created all the data in TM1 rules. The logic behind this was that we can easily export the rule-based calculations, delete the rules, then import the data as static numbers, so this technique just gives us an option to keep a rule-based lookup if we ever want to.

In the previous version of Propel, changing the start month was quite a significant effort. We had a Turbo Integrator function to do all the hard work, of course, but it had quite a lot to do – updating attributes, shifting data around in the date lookup, reordering elements. We even had a hidden cube that would provide data to the final date lookup when the TI process was run.

We realized this time round the designing a smarter, more flexible date lookup cube, along with the Month and Year Period dimension would make this configuration much simpler, and render most of the tomfoolery in the TI process unnecessary.

Here is the new data structure:

Generic Month & Year Period Elements

The most important part of designing this cube was avoiding the need to rename elements in the Month and Year Period dimensions. Instead of using “Jan”, “Feb”, “Mar” for the Month element names, we instead used “M01”, “M02”, “M03”, etc. Likewise, the Year Period dimension contains the elements “Y01”, “Y02”, “Y03”, etc.

This gives us freedom to interpret each month element as a particular named month, based on the Fiscal Year. So, in Australia, we would simply set the “Display Name” attribute on “M01” to “Jul”, and similarly for subsequent months.

Now we can always assume the element name “M01” is the first month in the fiscal year.

But it’s not quite that easy. We still need to make sure our date lookup cube calculates the correct calendar month for each Fiscal month.

Fiscal Month Offset

In order to do this, we use a simple attribute in the Month dimension called “Fiscal Month Offset”. This value is referenced by the date lookup cube when calculating the calendar month. The numeric value represents the number of months to “shift” the calendar month from the fiscal month.

For instance, if our fiscal year starts in July, we need to put a 6 in this value. The date lookup rules will then equate “M01” to “M07”, which is calendar month Jul.

This way, we can still look up calendar dates if need be.

Calendar vs Fiscal Date Measures

Hence, the date lookup cube supports two sets of measures, one for lookups that occur within the fiscal year, and another for lookups to calendar years. The simplest lookup is now to the fiscal year, with no requirement to translate to calendar month and back again to do a simple lookup.

Other Improvements

To reduce the number of measures, we also removed the “Backward” and “Forward” measures. This is now done using the “Offset Month” and “Offset Year” dimensions, which now include negative numbers.

This is more articulate, and simplifies rules which rely on numeric calculations to determine the number of months to search forward or backwards in time.

Example Usage

To lookup 3 months in the past from a fiscal-based cube:

# Lookup the year

DB('SYS Fiscal Date Lookup',

	!GBL Year, !GBL Year Period, !GBL Month,

	'0','-3',

	'Target Fiscal Year');

# Lookup the month

DB('SYS Fiscal Date Lookup',

	!GBL Year, !GBL Year Period, !GBL Month,

	'0','-3',

	'Target Fiscal Month');

Conclusion

With the new cube structure, it is much easier to lookup months and years in the past and future in fiscal-based cubes. Concordantly, it is no more difficult to use the cube in a calendar-based design.

Now where we’re going, we… er… don’t need roads… Sorry, I know it doesn’t really fit, I just wanted to say it.

Flow OLAP