By describing object characteristics in as-is state Aasis, constraints
are specified as prerequisites ðPR : AasisÞ. Some attributes
of the building elements change during the execution of the construction process. After the completion of the construction process,
the building elements are in target state Atarget . The description of
the characteristics of the building elements in target states represents
the results ðRE : AtargetÞ. If the complete triple prerequisitetask-
result sðPR; T; REÞ is specified, the solution ðsSÞ of a problem
is defined. Hence, the solution of a problem for construction scheduling
is represented within CBR as task-constraint grouping.