在lead一个team的时候，怎么样来应对人员流失而导致项目进度受到影响呢？其中可以思考的一个问题是公车因子(Bus Factor).我们先来看看Bus Factor的定义：
The "bus factor" is the minimum number of team members that have to suddenly disappear from a project before the project stalls due to lack of knowledgeable or competent personnel.The bus factor is a measurement of the risk resulting from information and capabilities not being shared among team members, from the phrase "in case they get hit by a bus".
核心概念是管理关键人物流失的风险。比如你的开发人员可能会休假，离职等。公车因子越大代表关键人物流失导致项目受到影响的概率越小。
For instance, say a team of 30 people produces bread in three necessary steps: mixing ingredients, kneading the dough, and baking. Ten people know how to mix ingredients, all 30 people know how to knead the dough, and 5 people know how to bake. If all 5 people who know how to bake disappear, then the team cannot produce bread, so the team's bus factor is 5.
如果你的team中的每个人做的东西都不一样，然后互相之间也不知道对方做的什么和怎么做，那么你的team的公车因子就是1.代表你的team在因人物流失而产生的风险很大。如果你的team中的每个人做的东西互相之间也都知道对方做了什么和怎么做，也就是说可替代，那么你的team的公车因子就是N(Team Member)。代表你的team在因人物流失而产生的风险很小。
作为开发经理，如何提高公车因子呢？进行design review, code review, tech session sharing可以很好的增大公车因子，基本原则是增加communication，讨论等活动。
原文:http://blog.csdn.net/hongchangfirst/article/details/79386602
作者:hongchangfirst
hongchangfirst的主页:http://blog.csdn.net/hongchangfirst