Blessed Pope John Paul II of happy memory changed the process of beatification and canonization dramatically.
Pope John Paul II changed this process dramatically. First, he put the responsibility for gathering evidence into the sole hands of the local bishop. More importantly, he abolished the entire legal system that had grown up around the canonization process and in its place made critical biographies his primary method for determining sainthood. The news shocked the Catholic hierarchy—lawyers lost their jobs and ecclesiastical historians gained new status. - John Paul II's "Canonization Cannon
More information on the various changes can be seen in this article: Canonization: Old vs. New Comparison
It is often noted by those skeptical of modern canonizations that the procedures by which the Church raises saints to her altars have been "changed" since the Second Vatican Council. What were these changes? Pope Paul VI began the process in 1969. His decree Sacra Ritua Congregatio split the Congregation of Rites into two congregations: the Congregation for Divine Worship and the Congregation for the Causes of Saints. The latter congregation was sub-divided into three offices, which led in turn to a restructuring of the canonization process. Between 1969 and 1983, the process in a sort of flux. In 1983, St. John Paul II's Divinis Perfectionis Magister further streamlined the procedure, eliminating much of the back-and-forth that characterized the pre-1969 procedure, as well as famously downgrading the office of Promotor Fidei ("Devil's Advocate") to make the office less adversarial.
But in what other ways do the pre-1969 and post-1983 procedures differ? How much has really changed in this process?
To help answer this question, we have prepared a side by side comparison of the pre-1969 procedure (which had remained relatively unchanged since 1588) with the post-1983 restructuring. Please note, because the years between 1969 and 1983 were a kind of interim period where the process was in flux, it is not included here, although a study of the changes in procedure during this period would be very illuminating. We present merely the pre-Paul IV system contrasted with the revisions made by John Paul II in 1983, revisions which characterize the current procedure followed in beatifications and canonizations.
Essentially, while the modern canonization procedure maintains the nuts-n'-bolts of the pre-1969 system, the aspect of "checks and balances" that characterized the pre-1969 procedure is weakened. The rigid oversight is missing in the contemporary system. We will not review this entire argument, but recommend the reader consult our lengthy article "History of the Devil's Advocate" for more on how the character of canonization has changed.