This chapter provides a glimpse of design theory. A directory is often a strategic project for the whole enterprise, so a proposal defining the project’s goal assumes a particular importance and is typically scrutinized closely by top management. Costs aside, they want to see a clear definition of two things: Goal of the directory services project and Metrics to determine whether the goal of the project has been achieved. The target of the project describes who in the end will benefit from the project. The target can also be called the end user. The schema defines the rules to obey when putting data into the directory. It defines which data can be put into the directory and the format of that data. It also defines how comparisons should be executed in the case of queries. When the directory server receives a query from a client, the server decides whether it is competent to answer the query.