Could Spreadsheets Crash the City?

I research into ways of building spreadsheets more safely, which is why I have spreadsheet cartoons. A good way to make any system easier to build is to stock prefabricated components, tested and documented. Even should these be not free, the money spent buying them is probably less than the wages saved — if you doubt this, try building a radio from transistors you fabricated yourself. And, once you have finished a complicated system, you help others by breaking it into components they can reuse.

Computing calls program components "modules", and speaks of "modular programming". Sadly, the world's most popular spreadsheet, Excel, lacks modules. If you write an Excel spreadsheet and want to give your code to someone else writing an Excel spreadsheet, you must copy and paste cells into their spreadsheet. Not possible if the shapes and positions don't match, and always at risk from errors. So I was pleased when I developed software to solve the problem; and I drew these cartoons for the European Spreadsheet Risks Interest Group conference where I showed off the software.

I actually blogged this entry in June 2010, when I created this cartoon blog. However, most of my cartoons are older, and I've given them the dates on which I drew them, because a few refer to current events. This one, I drew on July 6th 2005. The conference opened on July 7th 2005 in Greenwich, opposite Canary Wharf. Around eleven on that dreadful morning, we learnt of the bombings. The more terrifying because rumour flew. We heard London was "in lock-down", no-one allowed in or out. The conference chairman asked me whether I thought it tactless to show my first cartoon. Myself, I don't see the tactlessness.