The next step in the analysis-synthesis process is to reduce the total set of (formally) possible configurations in the morphological field to a smaller set of internally consistent configurations representing a "solution space". This is achieved by a process of cross-consistency assessment (CCA). All of the parameter values in the morphological field are compared with one another, pair-wise, in the manner of a cross-impact matrix. As each pair of conditions is examined, a judgment is made as to whether - or to what extent - the pair can coexist, i.e. represent a consistent relationship. Note that there is no reference here to direction or causality, but only to mutual consistency. Using this technique, a typical morphological field can be reduced by up to 90 or even 99%, depending on the problem structure.

There are two principal types of inconsistencies involved: purely logical contradictions (i.e. those based on the nature of the concepts involved); and empirical constraints (i.e. relationships judged be highly improbable or implausible on empirical grounds). Normative constraints can also be applied, although these must be used with great care, and clearly designated as such.

When this solution (or outcome) space is synthesized, the resultant morphological field becomes an inference model, in which any parameter (or multiple parameters) can be selected as "input", and any others as "output". Thus, with computer support, the field can be turned into a laboratory with which one can designate initial conditions and examine alternative solutions.