My former boss was a PSP/TSP certified software developer. He said studios had shown that programmer can work 4 hour/day and plans should be made accordingly (

My former boss was a PSP/TSP certified software developer. He said studios had shown that programmer can work 4 hour/day and plans should be made accordingly (e.g., if you have 16 hours to solve set of tasks, plan for four days, not two). He also said that this statistics was actually proven true during the course of their training and later in the practical application. Other four hours of "work" time is related to documentation and social aspects of development, like discussing ideas and plans.