Talk:Bus factor

Latest comment: 9 months ago by John Broughton in topic Additional sources

Is high bus factor good or bad ? edit

It appears that high bus factor means that a lot of people have to be incapacitated to disable a project, which is good. The bus factor in itself is something bad. Think: A bus accident is bad. In a bus accident, the bus is a factor. It has a high "bus factor". In common language you could say that something has a bus factor if the bus factor is a problem. On the other hand, if it is not on the horizon one could probably say, there is no bus factor involved. With this usage a zero bus factor is good and more than zero is bad, which is contrary to the definition.

It would be more straight-forward if the definition followed common logic - high bus factor is bad (which could be problematic to express numerically). Choosing a more positive name could help, e.g. bus survival factor. Any of those are difficult to do if the current usage is spread.

In any case a clarification should be made in the article. I didn't do it because I'm not sure if I get it right myself. Misiu mp (talk) 18:06, 15 August 2011 (UTC)Reply

Usage varies. On the one hand, Coplien and Harrison (reflecting Coplien's early work) write[1], "Define the truck number as the number of people in the organization who have unique critical domain expertise. You don’t want the truck number to be large, because that means that the probability is large that the loss of any given team member would mean the loss of critical expertise.... Keep the truck number low, thus retaining a small number of key experts with unique knowledge." On the other hand, the Debian reference[2] says, "A bus factor <= 1 is very bad."
taikedz (talk) 09:26, 8 June 2017 (UTC) :: I'd assert that the contradiction comes from the idea that zero is a valid number - another way of thinking of it is, if everyone has the knowledge, then it would mean taking out the entire team/company to stall the project. This number is not zero; zero could imply that there is no organisation to remove persons from in the first place, or that the knowledge is not required at all. Following that line of logic, bus factor cannot be zero, and a high bus factor is better.Reply


  1. ^ Coplien, James; Harrison, Neil (2004-07-26). Organizational patterns of agile software development. Wiley.
  2. ^ Reinholdtsen, Petter (2005-11-11). "Re: Resignation and uploads" (Mailing list).

Linux edit

The provided reference doesn't support the claim made for it. It actually says that obviously the bus factor for Linux isn't one, and then goes on to suggest a pointless experiment.

Other Linux trees have been maintained without Linus, the maintenance trees (for 2.4 and 2.2) are maintained without Linus, as are the short-lived stable trees like 2.6.18.x and various trees like AC have thrived without Linus. As have those architecture trees which for whatever reason didn't get frequent merges. If a better reference can't be found, this claim, and arguably the whole article, should go. (talk) 13:25, 19 March 2008 (UTC)Reply

Actually, I think the reference is to a definition, example of use, and such. A better reference should be sought, though, yes. —AySz88\^-^ 16:28, 1 May 2008 (UTC)Reply
The article author understands this too so he mentioned that it only is considered for the vanilla tree so I am going to specify the example better in the article. Tempust (talk) 14:38, 23 July 2010 (UTC)Reply

The correct term is Truck Number, see and JonathanWakely (talk) 13:38, 7 January 2009 (UTC)Reply

Bad History and opposites edit

The phrase as a generic unfortunate event dates back to at least 1907 when Joseph Conrad used it in The Secret Agent - So saying that "An early instance of this sort of query was when Michael McLay publicly asked what would happen to the Python language if Guido van Rossum were hit by a bus." is plainly nonsense, that is an example of a late instance, not an early one. (Lawrie (talk) 23:44, 13 May 2015 (UTC))Reply

The whole History section is written really badly. --Manys (talk) 00:16, 28 December 2015 (UTC)Reply

See Also edit

Why should I also see Cross-training? It seems completely unrelated. (talk) 18:16, 8 July 2009 (UTC)Reply

Welcome to Wikipedia, and remember to Be bold! I've removed it. Shreevatsa (talk) 20:48, 8 July 2009 (UTC)Reply
Cross-training reduces the bus factor. For instance, if you are the only person who can update the company's website, and you teach the accountant how to update the website (that's called cross-training), then you just multiplied the bus factor by two. Syced (talk) 04:07, 4 December 2015 (UTC)Reply

Decrease bus factor edit

Would it be fair to say that the following decrease the bus factor?

  • Open source
  • Open standards
  • Documentation (so a new developer/employee/engineer can join and pickup)
  • Developers from different companies/organizations/universities/labs (so layoffs on one company don't affect the employees of the other company)
  • Geographically distributed developers
  • Developer anonymity (so developers cannot be targeted in attacks)
  • Presence of independent developers (not tied to salary, not tied to direction/orders/decisions of higher management)

If so, maybe it could be added to the article. -- Frap (talk) 12:47, 4 September 2012 (UTC)Reply

Sounds good, feel free to add, be sure that each fact is backed up by a reference. Syced (talk) 04:09, 4 December 2015 (UTC)Reply

Formula edit

There needs to be a formula associated with: "A recent study calculated the bus/truck factor of 133 popular GitHub projects. The results show that most of the systems have a small bus factor (65% have bus factor ≤ 2) and the value is greater than 10 for less than 10% of the systems.[9][10]" — Preceding unsigned comment added by Bostwickenator (talkcontribs) 18:43, 4 May 2016 (UTC)Reply

Illustration edit

Will the project fail if this member is hit by the bus?

This article severely lacks illustrations.

I added this picture/label to helps people understand where this metaphor comes from. It is useful to anyone who does not already know the "hit by a bus" cliché. It is especially needed by non-native speakers who might be left wondering whether we are talking about a serial bus.

But an IP reverted it :-/

Is this picture bad for the article? What do you think? Thanks for your feedback! Syced (talk) 11:01, 7 October 2016 (UTC)Reply

rvtd back Johnbod (talk) 11:30, 12 October 2016 (UTC)Reply

Can't just use a random image of a bus, I don't think, see:MOS:IMAGERELEVANCE. -- (talk) 07:35, 23 May 2019 (UTC)Reply

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Is "Keith Forbes factor" actually used anywhere? edit

There's no citation for the phrase "Keith Forbes factor", no Google hits except for the page itself, and nothing relevant on the Keith Forbes page.

So where is this term ever used?

--Streapadair (talk) 10:04, 4 June 2018 (UTC)Reply

Joseph Conrad Quote edit

I'm not sure how the Joseph Conrad quote in the history section applies - maybe more context is needed? I read the entry on The Secret Agent and it doesn't really shed any light on how it applies to this concept. — Preceding unsigned comment added by (talk) 19:06, 10 October 2018 (UTC)Reply

Question about self published source in "Increasing the bus factor" edit

There is a a blog post supporting the points in the "Increasing the bus factor" section. Since it is a self published source, possibly unreliable I think it should be replaced with a better one or removed.

Additional sources edit


-- John Broughton (♫♫) 21:00, 1 August 2023 (UTC)Reply