Search methods and locating errors

The following search methods allow users to locate errors or problems in a file in different ways.

In both cases, the starting point is a model or file that contains an error, but the problem causing the error is unknown and has not been located. The problem should be located using a search method that includes trial and error tests after deleting groups of elements.

Sequential search

This method performs a sequential search by deleting elements or parts of the model (e.g. floors) one by one until the error is found.

Example

Model of a building structure with 5 floors (ground, 1, 2, 3, and 4). The error is on floor 2, but its location is unknown. The following search procedure is used:

• A backup of the file is made.
• Floor 4 is deleted. The error still appears.
• Floor 3 is deleted. The error still appears.
• Floor 2 is deleted. The error no longer appears. The error is on floor 2.

Binary search

This method carries out a binary search by deleting halves of the model until the error is found.

Example

Model of a water supply installation with a common supply connection and two risers supplying the two parts of the installation (I and II). Each riser supplies 2 dwellings (dwellings IA, IB, IIA and IIB). The error is in house IIB, but its location is unknown. The following search procedure is used:

• A backup of the file is made.
• I is deleted. The error still appears.
• The original file is recovered.
• II is deleted. The error no longer appears. The error is on II.
• The original file is recovered.
• IIA is deleted. The error still appears.
• The original file is recovered.
• IIB is deleted. The error no longer appears. The error is on IIB.

Limitations

• The proposed methods require that the models resulting from the deletion of part of the information from the file are consistent and can be calculated if needed. Furthermore, they must represent the original situation.
  
• If the error is not located at a specific point in the model, these methods will not yield valid results.
  
• Similarly, if the error appears in multiple locations, the procedure to find them may be more complex.