[adrianN]

Just like I wouldn't want to live in a house built from LEGO, I'm somewhat wary of Excel models as the basis for investment strategies in major banks. The problem with the quick and hacky solution is that it's never replaced, because that would cost money, and the current solution "looks like it works".

[iofj]

However the excel solution has a lot of things going for it :

1) applications/reports built by the people designing and understanding the underlying needs and inner workings of whatever they're offering. Whilst very good programmers can match this (given enough - that's a lot - time), average programmers won't even try.

2) excel sheets require nowhere near the manpower required for your alternative. That factors into a cost-benefit analysis that may not favor real development.

3) Speed of development. Markets change. Investments change. Sometimes literally in minutes. Anything involving more than 1-2 people who are intimately involved in the strategy itself cannot possibly keep up.

4) Excel is in fact a pure functional programming language [1]. Unless you deeply understand excel I wouldn't be so quick to call it stupid. There are entire classes of bugs that simply can't exist in excel spreadsheets that are regularly found in programs.

[1] http://ndc-london.com/talk/pure-functional-programming-in-ex...

These sheets are pretty good. You can really get nice app ideas from some of them: http://www.exinfm.com/free_spreadsheets.html

[osullivj]

1) is priceless. In banks I've seen many traders build pricing and risk solutions in Excel that would take weeks or months for developers who don't understand the products and/or maths to build. In some games, time to market is everything.

[collyw]

"excel sheets require nowhere near the manpower required for your alternative. That factors into a cost-benefit analysis that may not favor real development."

Not to build, but to maintain and constantly clean up the errors by using the wrong tool for the job. I know form experience having wasted countless hours because my organisation insisted on using it as a tool to upload data to our database, and using it as the database before that.

[nommm-nommm]

The errors they invariably introduce are also very expensive. Not just fixing them, but actions on incorrect data can be very very expensive. I've seen it, and in my experience its almost universal.

I'm not saying Excel is always the wrong solution, I am saying Excel is not always the right solution but it can appear to be. That makes it very dangerous.