Provide a quiet environment with plenty of space for each developer. Try to follow the example of Microsoft and provide offices with doors that close. Unfortunately, most companies do not have the resources of a Microsoft. If cubicles must be used, then provide good quality headphones so that developers can work in silence as much as possible. Also, provide a do-not-disturb sign that can be hung on the back of the developer’s chair or at the front of his cubicle. The rationale from this comes from the book PeopleWare by DeMarco and Lister 1999, which is paraphrased from Glass’s Facts and Fallacies book under fact 4:
Software work is thought-intensive, and the environment in which it is done must be one that facilitates thinking. Crowding and the resulting interruptions are deadly to making progress.
In PeopleWare, the authors performed a study of a project team. They separated the top quartile of performers from the bottom quartile (the top quartile outperformed the bottom quartile by a factor of 2.6 to 1) and then examined the working environment of both groups. The top people had 1.7 times as much workspace (measured in available floor space in square feet). Twice as often, they found their workspace acceptably quiet. More than 3 times as often, they found it acceptably private. Between 4 and 5 times as often, they could divert phone calls or silence their phone. They were interrupted by other people (needlessly) about half as often.