1. A computer implemented method for managing workflow instance migration, the computer implemented method comprising: comparing, with a migration manager communicatively coupled to a memory and a processor on an information processing system, an initial workflow process model with a new workflow process model; determining a set of differences between the initial workflow process model and the new workflow process model; identifying, with the migration manager, based on the set of differences, at least one set of a plurality of activities associated with the initial workflow process model that is migrateable to the new workflow process model; and generating a migration plan associated with the initial workflow process model and the new workflow process model, wherein the migration plan comprises the at least one set of the plurality of activities associated with the initial workflow process model that is migrateable to the new workflow process model; and wherein the identifying further comprises: identifying, with the migration manager, a set of migration constraints based on the set of differences, wherein the set of migration constraints identifies at least one set of a plurality of activities in the initial workflow process that are non-migrateable to the new workflow process model; and identifying, with the migration manager, based on the set of migration constraints, the at least one set of a plurality of activities that is migrateable to the new workflow process model; and wherein identifying the set of migration constraints further comprises: identifying at least one set of a plurality of activities within the initial workflow process model associated with each migration constraint in the set of migration constraints; identifying, for each of the at least one set of a plurality of activities, a first activity in the set of activities and a last activity in the set of activities; annotating, for each of the at least one set of a plurality of activities, the first activity, the last activity, and all intervening activities as non-migrateable with respect to the new workflow process model; identifying at least one remaining set of a plurality of activities within the initial workflow process model that has not been annotated as non-migrateable; and identifying the at least one remaining set of the plurality activities as a set of migration points for the new workflow process model, wherein the at least one remaining set of a plurality of activities is identified as the at least one set of a plurality activities that is migrateable to the new workflow process model; and wherein identifying the at least one remaining set of a plurality of activities further comprises: determining an activity type associated with each migration point in the set of migration points; identifying, based on the determining, a subset of the set of migration points comprising an activity type that fails to be a migrateable activity type; and removing the subset of migration points from the set of migration points creating a new set of migration points; and determining, for each migration point in the new set of migration points, (1) a position of the migration point within the initial workflow process model relative to each set of the plurality of activities associated with each difference, and (2) whether the migration point is filterable; and wherein the migration plan comprises at least the new set of migration points, the position of each migration point in the new set of migration points, and a marking of each migration point as filterable or not-filterable, wherein the at least one set of a plurality of activities that is migrateable to the new workflow process model is associated with the new set of migration points.