BIB-VERSION:: CS-TR-v2.0
ID:: UCB//S2K-93-25
ENTRY:: February 28, 1994 
TITLE:: DARWIN: On the Incremental Migration
        of Legacy Information Systems  
DATE::  
AUTHOR:: Brodie, Michael L. 
AUTHOR:: Stonebraker, Michael  
PAGES:: 32 
ABSTRACT:: As is painfully evident today, the deterioration
of the transportation, education, and other national infra- 
structures negatively impacts many aspects of life, business,
and our economy. This has resulted, in part, when responses
to short term crises discourage investing in infrastructure
enhancement and when there are no effective information system
(IS) insfrastructure that has strong negative impacts on ISs,
on the organizations they support, and, ulimately, on the 
economy. This paper addresses the problem of legacy IS migration
by methods that mediate between spectrum of supporting methods
for migrating legacy ISs into a target environment that includes
rightsized  hardware and modern technologies (i.e., infrastructure)
wuch as client-server architecture, DBMSs and CASE. We illustrate 
the methods with two migration case studies of multi-million dollar,
mission critical legacy ISs. The contribution of this paper is a 
highly flexible set of migration methods that is tailorable to most
legacy ISs and business contexts. The goal is to support continuous,
iterative evolution. The critical success factor, and challenge in
deployment, is to identify appropriate portions of the IS and the
associated planning and management to achieve an incremental migration 
that is feasible with respect to the technical and business require-
ments. The paper concludes with a list of desirable migration tools
for which basic research is required. The principles described in
this paper can be  used to design future ISs and an infrastructure 
that will support continuous IS evolution to avoid future legacy
ISs. 
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END:: UCB//S2K-93-25