# CP028: How to tell business logic & rules to Excel?

Posted on January 22nd, 2015 in Chandoo.org Podcast Sessions , Random - 6 comments

In the 28th session of Chandoo.org podcast, let’s figure out how to express business rules & logic to Excel.

### What is in this session?

What good are spreadsheets if they can’t solve business problems?

But we all struggle when it comes to modeling real world business conditions in Excel. For example, if you have below business rule to decide how much discount to offer a customer,

• If the customer bought 3 or more times previously and offer 15% discount
• If the customer bought 1 or 2 times previously AND customer’s age is >40, offer 10% discount
• If the customer visited our New York store between 6PM-9PM offer 5% discount
• Else no discount

How would you go about modeling these in Excel?

That is our topic for this podcast session.

In this podcast, you will learn

• The challenge of modeling business logic & rules in Excel
• My struggles with such formulas in early days
• 4 features of Excel that can help you with this.
• 1. Logical formulas
• AND
• OR
• NOT
• XOR
• 2. Support formulas
• IF
• IFERROR
• CHOOSE
• 3. Information formulas
• IS functions
• 4. Operators
• Brackets
• +*- operators
• Example business rules & how to write formulas for them
• Conclusions

### Links & Resources mentioned in this podcast

Logical formulas – Syntax & Examples:

Support functions & concepts:

Homework for you:

### What challenges do you face when modeling business rules / logic?

When I was learning Excel, I struggled a few years understanding the concept of logical functions. Of course I was in college, so I had all the time in world to explore and learn.

What about you? Do you write formulas that model real world logic? Where do you struggle? Please share your thoughts & inputs in comments section so that I can help you better.

### IF(AND(like chandoo.org, love podcast),

If you like chandoo.org & our podcast, please take a minute and do one or both of below:

Other options to subscribe

 3 Course Meal of Excel Awesomeness for You Doing Cost Benefit Analysis in Excel – a case study
 Written by Chandoo Tags: and(), choose(), Excel 101, if(), if() excel formula, Learn Excel, Microsoft Excel Formulas, NOT(), OR() excel formula, podcasts, XOR Home: Chandoo.org Main Page ? Doubt: Ask an Excel Question

### 6 Responses to “CP028: How to tell business logic & rules to Excel?”

1. Chaitanya Sagar says:

Love (podcast) AND Love (the picture) = TRUE

2. […] In his latest podcast, Chandoo figures out how to write business logic and rules in Excel formulas. […]

3. Neville says:

dear sir

I am unable to understand how to frame the syntax used in VBA. how can I understand the logic used in programming in vba

4. Mark says:

Thanks for great podcast! One thing on ISBLANK... I have found the using the syntax of IF(A1="") which is checking for a zero length string to be a more consistent tool than ISBLANK. In my experience ISBLANK is too restrictive due to how Excel defines blank cells. Checking for a zero length string is more robust for the modeling I have done. YMMV.

Anyway, thanks again and keep up the good work!

5. Sunny says:

Hi,

Linking data with timelines:

For E.g. the whole model is prepared on monthly basis from April to March.

Starting date of some of the variables is April 2014, some may be July 2014. Now if the timeline gets postponed than dates need to be changed and accordingly the whole model have to be shifted. How to automate the same. Meaning thereby the variable that has starting date in Apr 2014 will now shift to Sep 2014 and so on.

I think, following function need to be used: (if, and). But if the number of variables are very high (that are linked with timeline) it is becoming very difficult to manage...

6. Nishant bhardwaj says: