Implementing N-tier structure in .net

my requirement - suppose I have three classes namely Employee, Customer and Department. Employee contains attributes id, name, dept. Customer contains id and name. Department contains id and name. Now all three class have 开发者_开发技巧common functionality i.e. create, update and delete. I want to implement these functions using an interface. So can anyone sugest how I can perform these things in an n-tier architecture?

N-tier architecture splits an application into seperate tiers with a disctinct concern.

What you originally outline is about OO design, which is a bit different.

If you want to learn about implementing an OO design in an n-tier application, then Patterns of Enterprise Application Architecture would be a good start.