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RWA calculator

The story is as follows:

-          The new regulatory capital calculation rules were about to be mandated

-          The calculation rule looked quite complicated and one of the mega banks initiated a multi-million/year project with a software vendor

-          I developed an Excel alternative and made it available free to use by my colleagues

-          The user base of my calculator grew organically world-wide at the bank given its ease of use, efficiency, speed, and versatility

-          The engine I developed was copied to a few other calculator projects at the bank. It was effectively the gold standard

-          Years later the vendor solution was decommissioned

-          More than a decade later my calculator is still used at the bank by hundreds of users

Scary requirement

Apparently the look of the new regulatory requirement scared enough people, who signed up for multi-million/year project. Below screenshot is from the U.S. Federal Reserve describing the new regulatory rule. It is page 22 in the PDF reader of this document: https://www.federalreserve.gov/generalinfo/Basel2/FinalRule_BaselII/TechnicalOverview.pdf

The same rule is also found in the international version where other nations referred to. It is available at: https://www.bis.org/publ/bcbs107.pdf

In the past specifically for bank’s credit risk, regulatory capital requirement did not involve risk parameters or statistical functions such as cumulative distribution function. As such it is speculated that those in the regulatory capital job function might not have had expertise to assess the new regulatory capital rule that were driven mostly by risk parameters and statistical methodologies.

Excel solution that cost virtually nothing

What I came up with in a few days was as follows, from the user’s point of view:

           

You just put 4 arguments and you get the answer.

It is deceptively simple especially if you compare the original regulatory rule vs. the actual Excel implementation. The engine as per the regulatory requirement was hidden within VBA code. It turned out all the user had to provide was 4 inputs in order to compute RWA. I heard from my colleagues that the decommissioning of the vendor solution was done using my calculator to test the calculation accuracy.

My thoughts

It’s one thing to really understand the business requirement. It could be a whole another story to come up with a technical solution. My RWA calculator represented an elegant solution to what appeared to be very complex business requirements.

The fact it remains extremely popular amongst the end users is another key aspect that must not be ignored. Consider this: a project team celebrates successful implementation of a large project while the user community loves to complain the cranky user experiences. Today at least there are jobs for UI/UX specialists, but I’m afraid I have seen so many projects that totally ignored such aspects. RWA calculator I developed was actually designed so that I as an end user was content with its UI/UX. While the vendor package solution did at least the minimum the computation of the RWA, it was no match in many ways.

Last but not least, the calculator development was actually not the job I was hired for. I did it over a few days when I was not so busy with my own job.

 

The last update: 8/22/2018

The page has been designed and written by Ayumi Ozeki ozekia@gmail.com

go to home http://ayumi01.s3-website-us-east-1.amazonaws.com