1. IT Architecture
Technical blueprint for evolving a corporate infrastructure resource that can be shared by many users and services
processing systems
hardware
application software
operating system
telecommunications systems
data architecture

2. Requirements of an Effective Architecture
Provide as much vendor independence as possible
Be able to integrate incompatible elements
Incorporate standards either in use or likely to be adopted by leading vendors or electronic trading partners

3. Migrating from Mainframes to Client/Server
Gradual migration by
developing all new applications specifically for client/server environment
moving user interfaces from mainframe to PC and communications management to servers

4. Migrating from Mainframes to Client/Server
Gradual migration by (cont’d.)
move applications to workstations or PCs and leave the mainframe as a database server
move mainframe databases to smaller servers

5. Migrating from Mainframes to Client/Server
Move as much processing as close as possible to the user
Share as little as possible, e.g., only the data
Build peer-to-peer networks
Avoid migrating old code

6. Migrating from Mainframes to Client/Server
Simplify the enterprise-wide computing environment
Automate the management of the enterprise’s information architecture
Write as little code as possible

7. Reasons to Replace Applications
Code and documentation has suffered from years of changes and is now “fragile”
Documentation is out of date
Technology upgrade promises significant operating cost reduction

8. Reasons to Replace Applications
Current technology platforms are difficult to maintain
Business processes have been redesigned and new applications are required

9. Management Concerns About Replacement
High potential investment required
Lack of skill and experience with the new technology
Lack of availability of packaged solutions that could reduce replacement costs

10. Management Concerns About Replacement
Concerned that the need for replacement is technology-driven
Risks of replacement

11. Typical Methods Used to Decide on Replacement
Cost/benefit analysis that compares ongoing cost of maintenance and enhancement with the cost of replacement
Payback analysis based on benefits that could be obtained with the new system

12. Typical Methods Used to Decide on Replacement
Make-or-buy analysis that compares cost of new development with cost of acquiring and modifying a software package