One of the scaling factors called out in the Software Development Context Framework is “geographic distribution". As with the other scaling factors the level of geographic distribution is a range, with co-located teams at one extreme and far-located at the other. When your team is co-located the developers and the primary stakeholders are all situated in the same work room. If you have some team members in cubicles or in separate offices then you're slightly distributed, if you're working on different floors in the same building you're a bit more distributed, if you're working in different buildings within the same geographic area (perhaps your team is spread across different office buildings in the same city or some people work from home some days) then your team is more distributed, if people are working in different cities in the same country you're more distributed, and finally if people are working in different cities around the globe you're even more distributed (I call this far located).
As your team becomes more distributed your project risk increases for several reasons:
- Communication challenges. The most effective means of communication between two people is face-to-face around a shared sketching space such as a whiteboard, and that requires you to be in the same room together. As you become more distributed you begin to rely on less effective communication strategies.
- Temporal challenges. When people are in different time zones it becomes harder to find common working times, increasing the communication challenges. One potential benefit, however, is the opportunity to do "follow-the-sun" development where a team does some work during their workday, hands off the work to another team in a significantly different time zone, who picks up the work and continues with it. This strategy of course requires a high degree of sophistication and discipline on the part of everyone involved, but offers the potential to reduce overall calendar time.
- Cultural challenges. As the team becomes more distributed the cultural challenges between sites typically increases. Different cultures have different work ethics, treat intellectual property differently, have different ideas about commitment, have different holidays, different approaches to things, and so on.
As you would imagine, because the project risk increases the more distributed your team is, the lower the average success rates of agile projects decrease as they become more distributed. The 2008 IT Project Success Survey found that co-located agile teams has an average success rate of 79%, that near located teams (members were in same geographic area) had a success rate of 73%, and that far-located agile teams had a success rate of 55%. The success rate decreases similarly for project teams following other paradigms.
The practices that you adopt, and the way that you tailor the agile practices which you follow, will vary based on the level of geographic distribution of your team. For example, a co-located team will likely do initial architecture envisioning on a whiteboard and keep it at a fairly high-level. A far-located team will hopefully choose to fly in key team members at the beginning of the project, at least the architecture owners on the various sub-teams, to do the architecture envisioning together. They will likely go into greater detail because they will want to identify, to the best of their ability, the interfaces of the various subsystems or components which they'll be building.
Interestingly, the Agility at Scale 2009 survey found that it was quite common for agile teams to be geographically distributed in some manner:
- 45% of respondents indicated that some of their agile teams were co-located
- 60% of respondents indicated that some of their agile teams had team members spread out through the same building
- 30% of respondents indicated that some of their agile teams were working from home
- 21% of respondents indicated that some of their agile teams had people working in different offices in the same city
- 47% of respondents indicated that some of their agile teams had team members that were far located
The bottom line is that some organizations, including IBM, have been very successful applying agile techniques on geographically distributed teams. In fact, agile GDD is far more common than mainstream agile discussion seem to let on.