2004/07/04

Office Space

How important is the physical workspace to knowledge workers generally,and software developers specifically?  Everybody agrees it'simportant.  Talk to ten people, though, and you'll get nine differentopinions about what aspects are important and how muchthey impact effectiveness.  But there are some classic studies thatshed some light on the subject; looking around recently, they haven'tbeen refuted.  At the same time, a lot of people in the softwareindustry don't seem to have heard of them.

Take the amount and kind of workspace provided to each knowledgeworker.  You can quantify this (number of square feet,open/cubicle/office options).  What effects should you expect from,say, changing the number of square feet per person from 80 to 64?  Whatwould this do to your current project's effort and schedule?

There's no plug-in formula for this, but based on the available data,I'd guesstimate that the effort would expand by up to 30%.  Why?

"Programmer Performance and the Effects of the Workplace"describes the Coding War Games, a competition in which hundreds ofdevelopers from dozens of companies compete on identical projects. (Also described in Peopleware: Productive Projects and Teams.) Thedata is from the 1980's, but hasn't been replicated since as far as Ican tell. The developers were ranked according to how quickly theycompleted the projects, into top 25%, middle 50%, and bottom 25%.  Thecompetition work was done in their normal office environments.
  • The top 25% had an average of 78 square feet of dedicated office space.
  • The bottom 25% had an average of 46 square feet of dedicated office space.
  • The top 25% finished 2.6 times faster, on average, than the bottom 25%, with a lower defect rate.
  • They ruled out the idea that top performers tended to be rewarded with larger offices.
Now, whether larger workspaces improve productivity, or whether moreproductive people tend to gravitate to companies with largerworkspaces, doesn't really matter to me as a manager.  Either way, theanswer is the same: Moving from 46 square feet per person to 78 squarefeet per person can reduce the time to complete a project by a factorof up to 2.6x.  That's big.  (Of course there were other differencesbetween the environment of the top 25% and the bottom 25%, but they arelargely related to issues like noise, interruptions, and privacy.  Itseems reasonable to assume these are correlated with people density.)

It itself, this doesn't give us an answer for the question we startedout with (changing from 80 square feet to 64 square feet per person,and bumping up the people density commensurately).  As a firstapproximation, let's assume a linear relationship between dedicatedarea per person and productivity ratios.  64 is just over halfwaybetween 46 and 78, so it seems reasonable to use half of the 2.6factor, or 1.3, as a guesstimate.  So using this number, a project thatwas going to take two weeks in the old environment would take 1.3 timesas long, or around two and a half weeks, in the new environment.  (Inthe long term, of course.)

To put this into perspective, it appears that increasing an organization's CMM level by one generally results in an 11% increase in productivity, and that the ratio of effort between worst and best real-world processes appears to be no more than 1.43.

You can't follow the numbers blindly here.  This probably depends a loton the kind of work you actually do, and I can think of dozens ofcaveats.  My gut feeling is that the penalty is likely to be more like10% than 30%, assuming you're really holding everything else (noise,interruptions, etc.) as constant as possible.  I suspect that theorganizations which are squeezing people into ice cube sized cubiclesare likely to be destroying productivity in other ways as well.  But,these numbers do provide some guidance as to what to expect in terms ofcosts and consequences of changing the workplace environment.

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