1. Systems Analysis Requirements Determination Requirements Structuring
Alternative Generation and Selection
Generate a comprehensive set of alternative design strategies
Select the one design strategy that is most likely to result in the desired information system

2. Design Strategy
A particular approach to developing an Information System. It includes statements on:
Functionality
Hardware and software platform
Method of acquisition
Build or buy?

3. Software Alternatives
In-house developed software
In-house customization of a package
In-house software developed by contract personnel
End-user computing
Outsource a customized package
Vendor customizes its package
Vendor enhances its package
Package used with no modification

4. Reasons to build Satisfy unique requirements
Minimize changes in business procedures and policies
Meet constraints of existing systems and technology
Develop internal resources and capabilities

5. Reasons to buy Lower costs and time
Proven reliability and performance benchmarks
Requires less technical development staff
Future upgrade provided by the vendor

6. Customizing software
Vendor offers individual configurations for basic packages by adding on components
Pay the vendor to make enhancements to meet your individual needs
Buy the package and make your own modifications

7. Outsourcing Contracts
Can provide a cost effective solution for dealing with rapid technological change
Time and arrangements
Fixed price
Value added

8. ? Custom build Packaged system Outsource Business need Unique Common
Not core to the business
In-house expertise
Functional & technical
Functional only
Neither
Project skills
Desire to build skills
Skills are not strategic
Strategic decision
Time frame
Flexible
Short
Short or Flexible

9. Application Service Providers
Application hosting
Software as service
Internet is the delivery channel

10. Evaluating & Purchasing Packages
Evaluate the IS requirements
Identify potential vendors
Evaluate alternatives
Make the purchase
Install the package

11. Evaluate the IS requirements
Identify the key features of the system
Estimate volume and future growth
Specify any hardware constraints
Prepare a RFP or RFQ

12. Software Horizontal application Vertical application
Value added reseller

13. Software Vendors Hardware manufacturers Packaged software producers
Custom software producers (consulting firms)
Enterprise solution software
In-house development

14. Software Sources Producers Capabilities Hardware manufacturers
System software and utilities
Packaged software producers
Supports generic tasks
Custom
software producers
Custom support for systems that cannot be built internally
Enterprise-wide solutions
Complete systems that cross functional boundaries
In-house developers
System built from scratch

15. Criteria for Choosing Off-the-Shelf Software
Cost
In-house versus purchased
Functionality
Mandatory, essential and desired features
Vendor Support
Installation
Training
Technical Support
Viability of Vendor

16. Criteria for Choosing Off-the-Shelf Software
Flexibility
Ease of customization
Documentation
User documentation
Technical documentation
Response Time
Ease of Installation

17. Validating Purchased Software Information
Information from vendor
Software evaluation period
Customer references from vendor
Independent software testing service
Trade publications

18. Making the Purchase Software license Lease agreement
Maintenance agreement
Installation

19. Implementation Issues
Technical and social aspects of implementation need to be addressed
Training
Disruption of work

20. Alternative Matrix Shop With Me Web Shop Shop–N-Go Developed in C
Developed in C and Java
Developed using Java
Orders sent to company using files
Can export order information to other systems
Can save orders in several file formats
Easy to customize
Not easily customized
Widely used by other companies
Relatively new application
Brand new application
$150 initial fee
$700 up-front
$200 annually

21. Selecting the Best Alternative Design Strategy
Process
Divide requirements into different sets of capabilities
Enumerate different potential implementation environments that could be used to deliver the different sets of capabilities
Propose different ways to source or acquire the various sets of capabilities for the different implementation environments

22. Selecting the Best Alternative Design Strategy
Deliverables
At least three substantially different system design strategies for building the replacement information system
A design strategy judged most likely to lead to the most desirable information system
An updated Baseline Project Plan (BPP) for turning the most likely design strategy into a working information system

23. Generating Alternative Design Strategies
Best to generate three alternatives
Low-end
Provides all required functionality users demand with a system that is minimally different from the current system
High-end
Solves problem in question and provides many extra features users desire
Midrange
Compromise of features of high-end alternative with frugality of low-end alternative

24. Drawing Bounds on Alternative Designs
Minimum Requirements
Mandatory features versus desired features
Forms of features
Data kept in system files
System outputs
Analyses to generate outputs
User expectations on accessibility,response time and turnaround time

25. Drawing Bounds on Alternative Designs
Constraints on System Development
Time
Financial and human
Legal and contractual
Dynamics of the problem

26. Hardware and Software Issues
Existing Platform
Lower costs
Information system staff is familiar with operation and maintenance
Increased odds of successfully integrating system with existing applications
No added costs of converting old systems to new platform and limited data conversion costs
New Hardware and System Software
Some software components will only run on new platform
Developing system for new platform gives organization opportunity to upgrade technology holdings
New requirements may allow organization to radically change its computing operations

27. Alternative Systems Requirements A B C Real-time data entry Yes
Automatic re-order decisions
For some items
For all items
Real-time data on inventory levels
Not available
Available for some items
Fully available

28. Alternative Systems Constraints A B C Development cost $25,000 $50,000
$65,000
Hardware cost
Time to operation
3 months
6 months
9 months
Ease of training
1 week
2 weeks

29. Multi-criteria decision making
Weighted approach can be used to compare the three alternatives
Decision criteria are the Constraints and Requirements
Weights are arrived at by discussion with analysis team, users and managers
Each requirement and constraint is rated for each alternative
1 indicates that the alternative does not match the request well or that it violates the constraint
5 indicates that the alternative meets or exceeds requirements or clearly abides by the constraint

30. Updating the Baseline Project Plan (BPP)
The Baseline Project Plan (BPP) was developed during systems planning and selection phase
Baseline Project Plan (BPP) can be used as an outline of a status report at analysis phase
Schedule will be updated to reflect actual activities and durations
An oral presentation of project status is typically made at this phase

31. Transition to System Design
Logical Design
input
output
processes
Physical Design
system flow charts
DFDs & ERDs
CASE Tools

32. Physical DFD Add implementation references
in parentheses below each component
Draw a human machine boundary
a line that separates the automated from the manual parts of the system
Add system related process and data flows and stores
Technical limitations
Audits, controls or exception handling
Update the data elements in the data flows
Add system related data elements
Update the metadata in the CASE repository

33. Physical ERD Change entities to tables or files
Change attributes to fields
Add primary keys
Add foreign keys
Add system related components

34. Webstore System Requirements
Minimum
Full integration with current systems
99.9% uptime and availability
Essential
Flexibility and scalability
Desired
Technical support and/or emergency response
Documentation

35. Webstore System Constraints
Christmas season rollout
Small development/support staff
Transaction-style interaction with current systems
Limited budget for consultants

36. Alternative Systems Outsource ASP (Low-end)
All hardware located offsite
Application developed and managed offsite
Excellent emergency response
Inflexible
Difficult to integrate with current systems

37. Alternative Systems ERP system (High-end) Stability and documentation
Required skilled internal staff
Expensive hardware and software
Big learning curve

38. Alternative Systems Application server/object framework (Moderate)
Excellent integration with current system
Scalability and flexibility
Requires internal development and/or consultant
Proprietary

39. Best Alternative Design Strategy
Proposed system is a scalable, three-tier approach
Scalable
The ability to seamlessly upgrade the system through either hardware upgrades, software upgrades or both
Three-tier
Web Server
Provides connection to the Internet and presentation of HTML page
Applications Server
Middle layer of software and hardware that lies between Webserver and corporate network
Corporate network
Existing organizational computing infrastructure