Why Monte Carlo will change the way you make financial decisions and think about scenarios?


When you hear Monte Carlo simulation what do you think?

A racing game,

casino game or 

a financial decision.

The answer is hopefully the last 2…albeit in the casino it’s not your decision but certainly the houses decision over time for sure. 

I assume at this point you want the definition of Monte Carlo simulation.  Even some of the most advanced financial modelers are not entirely clear as to what it is mechanically and mathematically.

The official Wikipedia definition is defined as methods with a broad class of computational algorithms that rely on repeated random sampling to obtain numerical results. Their essential idea is using randomness to solve problems that might be deterministic in principle….

Sound easy to understand yes…let me simplify it for you.

Why is it that people just don’t get the power of more than 3 scenarios?

Why is this even important?

Whenever I meet professional finance people of all types and accountants in practice, the most they would think of analysing is 3 scenarios when it comes to “what-ifs” or “modeling”…for those that call it that…. maybe 5, and rarely 10. But never 1000’s.

Rather than having only 3 choices of outcomes imagine what it would be like to run scenarios that are a little closer to real life…isn’t that the whole purpose of doing the model in the first place?

Now we are talking about more than 1,000’s in some real life cases…..perhaps a lot more.

In reality there are probably millions of different scenarios and outcomes, but let’s just say 1,000 is good enough for now, certainly not 3, 5 or 10.

If only life were as simple as just 3 scenarios.

What do people do today?

Let me start at the beginning of forecasting 101…which hopefully many would be aware of or at the very least learn from:

1) Set a plan and a somewhat dynamic “budget” let’s say. Call it “what you told the bank” or the “listed equities market” what you guessed the profit would be. Using only 3 scenarios that’s probably what you are doing anyway…yes guessing.

Compared to Monte Carlo simulation where you are doing significantly more advanced scenarios and testing the outcomes, many times over.

2) Once you have collaborated with plenty of stakeholders to come up with the numbers it still takes time just thinking of 3 scenarios in the first place. Organisations move slowly so doing more scenarios means massively more manual work and cost, for little extra perceived value, so they just don’t do many scenarios and often stick with 3 (if you are lucky, sometimes only 1 scenario as the systems can only handle 1 budget).

Imagine for a moment how long it would take to get 10 or 100 scenarios for everyone to agree on….let’s say across 10 or 100 divisions or product owners. Near impossibility.

What could people do instead?

Here is a crazy idea…why not get them together in a room and decide on a range of outcomes between 2 extremes.

Just ask them to pick a range and let the model do the hard work for you. This is known as a simulation, where you are randomly generating the assumptions between outer limits.

How many finance professionals or business partners actually ask their stakeholder for a range.

Most organisation at group level might ask for 3 -10, but never 1000’s of scenarios.

Why is this valuable?

How much more valuable would that conversation be as it allows people to think more like real life, rather than being squeezed into a box of only 3 options?

Also, you will notice that very few accounting-based forecasting software packages (small or larger) can claim proper modelling techniques that do Monte Carlo Simulation…. only Excel at this stage from what I know, happy to be proven wrong.

So, the value of Monte Carlo is that ability to bring forecasts closer to real life. This is something many strive to achieve when building a forecast (ie replicate as close to real life as possible), but of course pretty much most would recognise that it’s difficult to predict the future with absolute precision…this isn't the point of this article. It's about getting more accurate than guess work.

Perhaps with Monte Carlo this future is slightly less opaque.

What will people do in the future?

Now take that very same picture of a Monte Carlo simulation and rather than clicking a macro button in Excel to run a simulation, you are Tom Cruise with some cool gloves on in a decision room and you are dynamically swiping your way through financial decisions and simulations….almost like Keanu Reeves in the matrix even!

I encourage you to also take a peak at my past/present articles on financial modeling which is the foundation of business decision making, planning and forecasting.

We have also redesigned our website to help you along your journey of levelling up in this space.

We will continue to discuss this topic and you can click to follow me on Twitter or LinkedIn or subscribe to our short but sweet newsletter.

Be sure to check out our pods and video page.

Here are also some past/present blogs that might be of interest.

Forecasting skills doesn't guarantee good modeling skills

How Technology Will Change FP&A Forever

Why so many unemployed accountants are already struggling..and how I can help?

Father battles cancer, son battles career extinction

Why being a 1-man/women VCFO business is a really bad idea?

Why Vlookup (vs Index(match) shows your lack of embracing change, innovation and better Excel skills

Why a Truly Integrated Business Planning Solution Requires a Flexible Dual Architecture known as Core and Edge.

Excel is dead!

Financial Modeling Innovation: Predictive analytics vs Financial Modeling

Financial Modeling: Diamonds in the rough

Driver Based Planning & Forecasting in the context of FP&A

Inside the mind of a spreadsheeter vs a financial modeler

Virtual CFO the Good, Bad and the Ugly

Part 3 of Finance Innovation – The Airbnb of spreadsheets - first major wave of spreadsheet innovation

Do You Model Off against the Masters of Financial Modelling?

NEED HELP searching for the best advisory tool in the market?

Part 2 of Finance Innovation - Data Analytics / Big Data is not Financial Modeling

Why I disrupted my own role and you should do the same?

Consulting, Advisory, Finance and the art of influencing is about to change forever.

Your Financial Model can save lives !

The Machines Are Not Coming… they are here!

Why financial modelling skills will be a big career door opener for emerging accounting and finance talent.

The Demand for Financial Modeling Skills Reaches new Heights

Lance Rubin is the Founder of Model Citizn, partner of theOutperformer, approved training provider to the Financial Modeling Institute and Group CFO for SequelCFO.

I have more than 20 years of combined experience working in model audit, investment banking, corporate finance, finance business partner and Fintech CFO.

Organisations I have worked with include PwC, KPMG, National Australia Bank, Investec Bank and Banjo small business lender.

I have a YouTube channel dedicates to the Future of Financial Modeling and also provide access to Models via Eloquens with thousands of viewers and downloads.