We consider only one load case, requiring only that the structure be able to support its own weight. The design criteria used are based on the AISC Manual of Steel Construction [1], as mandated by the 2003 International Building code [2]. The design criteria employed are industry standard. However, additional load cases would be required to account for additional loading such as live load, snow load, wind and seismic loading. The expensive component of fitness analysis determines whether each member will be in tension or compression under this load case, and then calculates a “unity check” for that member. A unity check greater than 1.0 means that the member fails to satisfy the load requirements.
The number of “violations” is the number of members with unity checks greater than one. If the unity check is less than
1.0 it means that the member is stronger than necessary, and could perhaps be reduced in size.