Excel; some sort of licensing?

[Sharky]

So, I've spent literally days/weeks/ages working on a financial model in Excel which will be given to the client. Now, I'm a protective kinda guy, and I don't want them thieving it for another project, but I do want them to be able to make slight changes.

Any ideas besides just locking down the main worksheets? Problem is, they need to export a lot of the data to a separate application to run Monte Carlo analyses etc.

I would upload a copy but it's confidential, and a few hundred MB's. It's already dependent on various custom functions coded in VBA so I suppose they could be deactivated?

[steronius]

When you say "slight changes" do you mean to the actual code? I think you can lock and hide the code. although password protecting your code could easily be cracked.

There is such a thing as "obfuscating" your code.... and also such a thing as compiling your workbooks into EXE. (although i've done neither)

You could also write your own EULA and require agreement -- while it may not prevent theft, it could bind legalities for litigation.

good luck!

[Sharky]

Nope, not the code, the data, and the settings behind the financial calculations.

[Smith6612]

If I'm not mistaken, shouldn't there be a way to lock an Excel Spreadsheet into Read-only mode? Wouldn't that work?

[essellar]

Forget technology. If you're providing data in a usable form (even if the intended use is only within your own application), then it's available to whoever physically has access to it. All you have at your disposal is a licensing agreement, and you want to be very careful writing that -- you've already told us that you're granting permission to re-use the data and to create substantially similar derivative works. I see body and feet in the picture, but there aren't many legs to stand on. Honestly, pricing this as though it was a purchase of an instance of the data (and reserving the right to use the data elsewhere yourself) rather than merely the right to use the data is the only way to go. If the data themselves are your value, then doing this as a service (web service or web app) and providing the summary analyses only is the only way you're going to be able to maintain sole ownership of the data.

[Sharky]

I copied out most of the proprietary stuff when it opens excel now asks about updating external data sources. It'll do for now.