Whereas a modern web software application has separate layers for presentation (
user interface), business
logic, and storage etc. (because modular construction is easier to build and debug) it is usually called an "
n-tier architecture", where
n represents the number of modules or layers. It is much more secure and robust than the "old way" (1-tier), where one
machine was the web server, file server, database, and firewall. A program which has illogical or insufficient rules (i.e. absence of business logic) can be termed "(
n-1) tier", as a crucial part (usually the part that makes the software smart or helpful) has obviously been omitted by scatterbrained developers, detached managers, clueless requirements analysts,
dumb pilot members, etc.
Employee A: Did you submit your travel costs yet?
Employee B: No, our stupid online expense system kept giving me a cryptic error.
Employee A:
Yup, that EOM app is an (
n-1) tier system...
Boss: I need you to fix your time charges for last week. You entered 45 hours instead of 4.5 hours on Wednesday.
Subject: Must've been a
fat-finger. Too
bad our accounting system can't catch that obvious error. It's just another (
n-1) tier waste of code.