4.3.3 Portioning the Reachability Matrix
According to Warfield [56], ”the
reachability set for a particular variable consists of the variable
itself and the other variables, which help the variable itself and to
form reachability set.” After that, the intersection of these sets is
computed for each of the components individually. The elements with the
same reachability and intersection sets occupy the top level of the ISM
hierarchy. The top-level element in the hierarchy does not contribute to
completing any other levels above it. After the top-level element has
been determined, it is isolated from the other elements in the
structure. The same method is utilized once more to determine the
components of the subsequent level. This procedure is repeated until the
level of each element is figured out. These levels give support to the
construction of the diagram and ISM model. Table 5 presents the
reachability set, antecedent set, intersection set, and levels for this
study’s 11 criteria (RE practices categories for GSD organizations in
the SSD process).