Copyright 2002 by
Prentice Hall, Inc.
10-13
How Can Legacy Systems be Improved?: Options
nRefurbish legacy systems  see Fig. 10-4
1.
1.Refurbish the input process - A front end can be added by using a 4GL DBMS to create a DB that combines fields from old files with new fields, then all input data flows into new DB
2.
2.Revise the Data Manipulation process - Once the new external DB is created, data from it and the original system can be merged and manipulated, e.g., project budgets and actual costs tracked differently - extract DB created to convert actual data to budget data format