We believe the more integrated, the better the firm is at using EDI, else it would not have committed to such a large extent. Therefore, the greater the extent of integration, the more satisfied the users. Similarly, the longer the firm has used EDI, the more satisfied we expect users to be. In other studies, years alone may only be part of the poor MIS success. Large scale, legacy systems that have been around for a long time may not be successful because they are outdated, awkward to use, or inefficient.
Years is only incidental.
With EDI, most firms have had the system in place less than 10 years, and because of the focus on success of the system, we believe that the longer it's been in place, the more opportunity the firm has had to make it effective, thereby increasing user satisfaction. Again, years alone, are not sufficient to explain satisfaction, thus the effect will be examined in light of other variables. We also expect user satisfaction to be higher when the application is more critical to the firm. Thus, for critical applications, we expect firms to do whatever is necessary to make the system a success. Applications may be more usable and effective, thereby increasing user satisfaction.