Version Control

Quick reference

• 00:04 The last thing I want to talk about,
• 00:06 before we start talking about the Excel functions we'll require for
• 00:10 financial modeling is the concept of version control.
• 00:13 I'm talking here about the actual file naming conventions.
• 00:19 People name files all sorts of things, but
• 00:21 I want to put my two cents into the melting pot if I may?
• 00:24 I will strongly recommend you save a file with a sequential
• 00:29 new name every few hours.
• 00:31 One of the things people are actually prone to do,
• 00:34 is they'll save a file as project Benjamin, project Xerxes, project Notty.
• 00:40 And these will be project names to actually protect people from revealing
• 00:45 confidential details to other people.
• 00:47 Because people then start to notice the Xerxes project,
• 00:51 rather than the fact that we're going to increase the price of apples by 20% or
• 00:55 something like that, which may or may not be confidential.
• 00:58 I'm all for really calling a file name a project to raise apples by 20%.
• 01:04 I'm putting it in a secure directory so
• 01:08 that people can't email it somewhere instead.
• 01:12 Because how often do you find you're looking for an old file months,
• 01:15 or years later and you can't actually remember the name of the project, and
• 01:19 you try to hunt it out?
• 01:21 It's something I've been modeling for 30 years, and struggle to find some projects
• 01:25 sometimes because I cannot remember what it was called.
• 01:29 That's up to you, though that's a subjective thing.
• 01:32 One thing I would recommend though, is putting at the end
• 01:37 of the file name a little version number like 1.01.
• 01:42 Now in Excel, it does have a tendency every now and then for a file to corrupt.
• 01:47 So every 2 hours or so, I'm tend to actually save the file
• 01:52 as version, 1.01, 1.02, 1.03, etc.
• 01:57 Therefore, if a file corrupts, I lose it, whatever, I've only lost
• 02:02 a maximum of two hours work because I can go back to the earlier version.
• 02:08 And if you've ever built a model,
• 02:10 you'll realize that what may have taken you two hours to do the first time,
• 02:14 you don't appreciate just how much thinking time there is in a model.
• 02:18 And you could actually do two hours worth of work in 15,
• 02:21 20 minutes the second time around, it's quite amazing.
• 02:24 I'm not calling you inefficient, we all do it.
• 02:26 Because we think, we iterate, we do it in different ways and
• 02:30 this is what I would do.
• 02:31 I also tend to put my initials in the file name as well, so
• 02:34 people know who actually built it just by looking.
• 02:37 As this is particularly useful if more than one person is going to be involved in
• 02:41 the build.
• 02:41 Now 1.01, 1.02, and
• 02:43 1.03 are going through that this is just interactive and incremental.
• 02:49 Sometimes you'll have a step change, 2.01.
• 02:51 This was the one that was submitted to the board, this is what I call a milestone.
• 02:58 Okay, I have a file now, that I'm gonna keep coming back to time and
• 03:01 time again, this is where I changed how depreciation calculated.
• 03:05 This is when I changed some key assumptions about revenue,
• 03:09 whatever it may be.
• 03:10 And they're the ones I document, rather than try and document every single change
• 03:14 in a model forever, which sometimes some of the auditors will ask you to do.
• 03:18 That's my two cents on this.
• 03:21 You end up with lots and lots of files in a directory.
• 03:23 But don't worry these days, we've got gigabytes,
• 03:27 we've got terabytes of space available.
• 03:30 Excel files rarely go over 35,
• 03:32 40 megabytes, sometimes they go a little larger.
• 03:35 But even so, you can store loads of these things.
• 03:38 And it's very useful to have these, both for audit trails,
• 03:42 and in case a version corrupts, recommended strongly.
• 03:46 Right, I think it's time to hit functions, don't you?

Lesson notes are only available for subscribers.