1. Design Completion A Major Milestone
System is Presented to Users and Management for Approval

2. Data Storage First, select the storage format Then optimize:
data storage efficiency
access speed

3. A good data model Simple, straightforward Minimize wasted space
Nonredundant (data integrity)
Flexible, adaptable to future needs

4. Physical ERDs Entities become tables Attributes become fields
Add primary keys
Add foreign keys
Add system related components

5. Optimizing Access Speed
Tradeoff between storage efficiency and speed
denormalization
archiving
indexing

6. Programming and Testing a New System
The Most Potentially Difficult Phase - ‘Reality Time’
Key Tradeoff: Development versus Maintenance Effort
Lead Programmer Has to Synthesize Many Members’ Work
End Users Assume Ownership of the Project
Ford Pinto example…

7. Planning the Programming Effort
Careful Selection of Milestones and Modularity of Programming Tasks are Important

8. Planning the Programming Effort
Programs Evolve in Stages:
program specifications
prototype
functional units
alpha test system
beta test system
production system
Windows 7 went production yesterday

9. System Programming and Testing
Can You Ever Expect a System to be Error Free?
Objectives at This Phase
Identify Flaws
Operational
Technical
Economic
‘If we didn’t release the program before it was completely tested, the
machines would be obsolete - and so would the program -
before they were delivered...’
Herbert Schorr, IBM

10. System Programming and Testing
Rigorously Test the System
Prepare the Site for Conversion
Prepare to Release the System to the Users

11. Implementation Planning
Testing:
Stub Tests
test individual routines with dummy linkages
Unit Tests
individual modules

12. Implementation Planning
Testing:
Program Tests
program tests with test data
loading in real data

13. Implementation Planning
Testing:
Integration Tests
related modules working together
System Tests
interfaces between program modules and other programs
data access and updating

14. Implementation Planning
Testing:
Acceptance Tests
user’s most critical role
system functions as expected
documentation sufficient
personnel adequately trained
operating procedures clear
appropriate liaisons with technical support staff

15. System Testing The focus here is on ERROR AVOIDANCE
The testing focus then migrates to ERROR DETECTION
then to ERROR ELIMINATION

16. System Tests Peak Load Test: extreme conditions
User - Hardware Interface: common usage problems
Recovery Test: simulate emergencies
Average Turnaround Time: verify processing levels

17. System Tests Documentation: user’s manuals
Storage: system’s ability to handle interim files
Communications: speed, security, accuracy
Use: gauge impact of user’s actions

18. Conversion and Implementation
Parallel
Evolutionary
‘Safest’
Not Always Feasible
Phased by Subsystems
Piecewise implementation of logically divisible components
Phased by Location (Single Location)
partial implementation in modules, such as divisions or outlets

19. Conversion and Implementation
Phased by Data Characteristic
Phased in functionality for a select subset of accounts
Crash (Direct)
worst for systems objectives, but often necessary
requires the most planning
Day One Changeover
minimal data conversion
restart company data base from ‘day one’

20. Training A Function of the Conversion Process Pilot Phased
cycle users through the new system
Phased
Implement around training schedule

21. Training Crash Parallel hopefuly, train on a prototype
alternately, train the trainers (cascading)
Parallel
several options, depends on temporary support
work beside the ne system and switch over
work with trainers running old system

22. Issues to Consider for Conversion Approach
Risk
Timing of Benefits
Development Time
Personnel Resource Requirements
Computer Resource Requirements
Current System Maintenance

23. Issues to Consider for Conversion Approach
Project Management Complexity
Ease of Verification
Training Impact
Fallback Feasibility