A method for determining a required solution subset from a set of solutions for eliminating a computer program execution error is provided. The method includes selecting a first candidate solution subset from a set of solutions for a computer program that produces an error when executed, wherein each of the solutions represents a different proposed modification of the program for eliminating the execution error, applying the first candidate solution subset to the computer program, thereby creating a first version of the program, selecting a second candidate solution subset from the set of solutions, applying the second candidate solution subset to the program, thereby creating a second version of the program, executing the first and second program versions to determine whether either of the executed program versions produces the error, adding the difference between the first and second candidate solution subsets to a required solution subset, when one of the executed program versions produces the error, and the other of the executed program versions does not produce the error, applying the required solution subset to the program, thereby creating a third version of the program, executing the third program version to determine whether the executed third version of the program produces the error and, if the third version of the program produces the error, repeating the above steps for different candidate solution subsets until the third version of the program does not produce the error.