title: Is it worth using 3-tier architecture for small(ish) applications
body: <p>I'm working on a relatively small asp.net web application and am wondering if there is really a need to employ full n-tier architecture.  For an idea of size; there are about 20 database tables.</p>
  
  <p>In the past I have used a 2-tier approach where business logic and data access are grouped together into a single class library with was an asp.net web application forming the UI tier and this seemed to work OK.</p>
  
  <p>Is there a threshold size or some rule of thumb where you should employ n-tier?</p>