Office Space

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

Take the amount and kind of workspace provided to each knowledge worker.  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?  What would 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 of developers from dozens of companies compete on identical projects.  (Also described in Peopleware: Productive Projects and Teams.) The data is from the 1980's, but hasn't been replicated since as far as I can tell. The developers were ranked according to how quickly they completed the projects, into top 25%, middle 50%, and bottom 25%.  The competition 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 more productive people tend to gravitate to companies with larger workspaces, doesn't really matter to me as a manager.  Either way, the answer is the same: Moving from 46 square feet per person to 78 square feet per person can reduce the time to complete a project by a factor of up to 2.6x.  That's big.  (Of course there were other differences between the environment of the top 25% and the bottom 25%, but they are largely related to issues like noise, interruptions, and privacy.  It seems reasonable to assume these are correlated with people density.)

It itself, this doesn't give us an answer for the question we started out with (changing from 80 square feet to 64 square feet per person, and bumping up the people density commensurately).  As a first approximation, let's assume a linear relationship between dedicated area per person and productivity ratios.  64 is just over halfway between 46 and 78, so it seems reasonable to use half of the 2.6 factor, or 1.3, as a guesstimate.  So using this number, a project that was going to take two weeks in the old environment would take 1.3 times as long, or around two and a half weeks, in the new environment.  (In the 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 lot on the kind of work you actually do, and I can think of dozens of caveats.  My gut feeling is that the penalty is likely to be more like 10% than 30%, assuming you're really holding everything else (noise, interruptions, etc.) as constant as possible.  I suspect that the organizations which are squeezing people into ice cube sized cubicles are likely to be destroying productivity in other ways as well.  But, these numbers do provide some guidance as to what to expect in terms of costs and consequences of changing the workplace environment.

Links and references:

• In How office space affects programming productivity (IEEE Computer  Vol. 28 No. 1; Jan 1995, pp. 7676) Capers Jones gives a guideline of at least 80 square feet of space per person, with full walls and doors, for optimal productivity.
  
• The most well-documented planning exercise for knowledge worker facilities is IBM's Santa Teresa facility; a discussion is here.
• Steve McConnell gives a good overview of this and other issues in Quantifying Soft Factors (IEEE Software Vol. 17 No. 6: Nov/Dec 2000, pp. 9-11).
• T. DeMarco and T. Lister , "Programmer Performance and the Effects of the Workplace", Proc. 8th Int'l Conf. Software Eng., ACM Press, New York,1985,, pp. 268-272.
• A great anecdote: Joel Spolsky, Bionic Office.  He's betting a lot of money that it's effective to equip his company with spacious, private offices.