This is a scaled down version:
http://msdn.microsoft.com/en-us/library/cc304370.aspx#_N-Tier_Flexibility_Relies>You may not need more than that for your apps. But if you have something that needs to communicate with a web service, a mainframe, some external device, you may add additional layers for each of those. Learn about Service Oriented Architecture (SOA) to see how it's done. A really good book is this one
http://www.amazon.com/Service-Oriented-Architecture-SOA-Technology-Computing/dp/0131858580/ref=pd_bbs_sr_2?ie=UTF8&s=books&qid=1212163535&sr=8-2>
>>Maybe I'm just locked into an idea I have been familiar with for a while but I don't know why I would need more than a GUI layer, a data layer, and a business rules layer.
.·*´¨)
.·`TCH
(..·*
010000110101001101101000011000010111001001110000010011110111001001000010011101010111001101110100
"When the debate is lost, slander becomes the tool of the loser." - Socrates
Vita contingit, Vive cum eo. (Life Happens, Live With it.)
"Life is not measured by the number of breaths we take, but by the moments that take our breath away." -- author unknown
"De omnibus dubitandum"
