Theoretical Justification of a Causal Model
RGURE 1 SHOWS A PROPOSED MODEL of the relationships among the factors in this
study. It shows that problems of the Organization, which generally exist at the start of
the SISP study, directly cause problems with Implementation, the final objective of
the study. Moreover, the problems of the Organization indirectly cause problems with
Implementation via their effects on Hardware, Cost, and Database.
The model is justified because the five factors correspond to the different phases
and activities of SISP as described in previous studies both by component and by
chronology. In terms of the traditional, three-phased input-process-output model of
SISP, Organization provides the input to the study. Cost is accrued during the process,
and Database and Hardware plans are produced dtiring the process [39]. Implementation
is the final phase of SISP and thus is also related to output [60].
From another perspective, the factors correspond to SISP activities [33]. Organization
maps to the first set of activities: organizational analysis and strategy-to-requirement
transformation. Database and Hardware map to the next set of activities: logical
design and logical-to-physical design. Since organizational analysis and strategy-torequirement
transformation precede logical design and logical-to-physical design
[33], Organization precedes Database and Hardware in the causal model. Implementation
maps to Karimi's final activity: implementation. Cost, namely the planning
budget, critically affects the success of SISP because it pervades the process while the
Hardware and Database plans are produced.
Besides broadly justifying the factors and their order, the impact of the factors on
each other can be examined. Also, the impact of individual problems of one factor on
those of another factor can sometimes be justified but not all problems from a factor
will necessarily affect all those in a related factor.^
Thus, the rationale behind each arrow in the model is now discussed in terms of how