1. Investigating and Determining System Requirements
Chapter 4
Investigating and Determining System Requirements

2. Performing Requirements Determination
Gather information on what system should do from many sources
Users
Reports
Forms
Procedures
6.2

3. Performing Requirements Determination
Characteristics for gathering requirements
Impertinence
Question everything
Impartiality
Find the best organizational solution
Relaxation of constraints
Attention to detail
Reframing
View the organization in new ways
6.3

4. Deliverables and Outcomes
Types of deliverables:
Information collected from users
Existing documents and files
Computer-based information
Understanding of organizational components
Business objective
Information needs
Rules of data processing
Key events
6.4

5. Traditional Methods for Determining Requirements
Interviewing and Listening
Gather facts, opinions and speculations
Observe body language and emotions
Guidelines
Plan
Checklist
Appointment
Be neutral
Listen
Seek a diverse view
6.5

6. Traditional Methods for Determining Requirements
Interviewing (Continued)
Interview Questions
Open-Ended
No pre-specified answers
Close-Ended
Respondent is asked to choose from a set of specified responses
6.6

7. Traditional Methods for Determining Requirements
Administering Questionnaires
More cost-effective than interviews
Choosing respondents
Should be representative of all users
Types of samples
Convenient
Random sample
Purposeful sample
Stratified sample
6.7

8. Traditional Methods for Determining Requirements
Questionnaires
Design
Mostly closed-ended questions
Can be administered over the phone or in person
Vs. Interviews
Interviews cost more but yield more information
Questionnaires are more cost-effective
See table 4-4 for a complete comparison
6.8

9. Traditional Methods for Determining Requirements
Directly Observing Users
Serves as a good method to supplement interviews
Often difficult to obtain unbiased data
People often work differently when being observed
6.9

10. Analyzing Procedures and Other Documents
Types of information to be discovered:
Problems with existing system
Opportunity to meet new need
Organizational direction
Names of key individuals
Values of organization
Special information processing circumstances
Rules for processing data
6.10

11. Modern Methods for Determining Requirements
Joint Application Design (JAD)
Brings together key users, managers and systems analysts
Purpose: collect system requirements simultaneously from key people
Conducted off-site
Prototyping
Repetitive process
Rudimentary version of system is built
Replaces or augments SDLC
Goal: to develop concrete specifications for ultimate system
6.11

12. Joint Application Design (JAD)
Participants
Session Leader
Users
Managers
Sponsor
Systems Analysts
Scribe
IS Staff
6.12

13. Joint Application Design (JAD)
End Result
Documentation detailing existing system
Features of proposed system
6.13

14. Prototyping Quickly converts requirements to working version of system
Once the user sees requirements converted to system, will ask for modifications or will generate additional requests
Most useful when:
User requests are not clear
Few users are involved in the system
Designs are complex and require concrete form
History of communication problems between analysts and users
Tools are readily available to build prototype
6.14

15. Prototyping Drawbacks Tendency to avoid formal documentation
Difficult to adapt to more general user audience
Sharing data with other systems is often not considered
Systems Development Life Cycle (SDLC) checks are often bypassed
6.15

16. Business Process Reengineering (BPR)
Search for and implementation of radical change in business processes to achieve breakthrough improvements in products and services
Goals
Reorganize complete flow of data in major sections of an organization
Eliminate unnecessary steps
6.16

17. Business Process Reengineering (BPR)
Goals (Continued)
Combine steps
Become more responsive to future change
Identification of processes to reengineer
Key business processes
Set of activities designed to produce specific output for a particular customer or market
Focused on customers and outcome
Same techniques are used as were used for requirements determination
6.17

18. Business Process Reengineering (BPR)
Identify specific activities that can be improved through BPR
Disruptive technologies
Technologies that enable the breaking of long-held business rules that inhibit organizations from making radical business changes
6.18

19. Summary Interviews Questionnaires Open-ended and close-ended questions
Preparation is key
Questionnaires
Must be carefully designed
Can contain close-ended as well as open-ended questions
6.19

20. Summary Other means of gather requirements
Observing workers
Analyzing business documents
Joint Application Design (JAD)
Prototyping
Business Process Reengineering (BPR)
Disruptive technologies
6.20

21. Requirements Discovery (Continued)
Selecting the Best Alternative Design Strategy
6.23

22. Learning Objectives Describe different sources of software
Learn to assemble the various pieces of an alternative design strategy
Learn how to generate at least three alternative design strategies
Discuss selecting the best design strategy using both qualitative and quantitative methods
6.24

23. Learning Objectives
Learn how to use the results of the analysis phase to update a Baseline Project Plan (BPP)
Discuss design strategies and how they are applied to the Internet
6.23

24. Selecting the Best Alternative Design Strategy
Two basic steps
Generate a comprehensive set of alternative design strategies
Select the one design strategy that is most likely to result in the desired information system
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
6.24

25. 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
A Baseline Project Plan (BPP) for turning the most likely design strategy into a working information system
6.25

26. 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
6.26

27. Drawing Bounds on Alternative Designs
Minimum Requirements
Mandatory features versus desired features
Forms of features
Data
Outputs
Analyses
User expectations on accessibility,response time and turnaround time
Constraints on System Development
Time
Financial
Legal
Dynamics of the problem
6.27

28. Issues to Consider in Generating Alternatives
Outsourcing
The practice of turning over responsibility of some to all of an organization’s information systems applications and operations to an outside firm
Can provide a cost effective solution
6.28

29. Issues to Consider in Generating Alternatives
Sources of Software
Hardware manufacturers
Packaged software producers
Custom software producers
Enterprise solution software
In-house development
6.29

30. 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
6.30

31. Criteria for Choosing Off-the-Shelf Software
Flexibility
Ease of customization
Documentation
User documentation
Technical documentation
Response Time
Ease of Installation
6.31

32. Validating Purchased Software Information
Information from vendor
Software evaluation period
Customer references from vendor
Independent software testing service
Trade publications
6.32

33. 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 or transferring data
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
6.33

34. Hardware and Software Issues
Request for Proposal (RFP)
A document provided to vendors to ask them to propose hardware and system software that will meet the requirements of your new system
6.34

35. Implementation Issues
Technical and social aspects of implementation need to be addressed
Training
Disruption of work
6.35

36. Internet Development: Selecting the 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
6.36

37. Summary Sources of Software Identifying requirements and constraints
Generating alternative design strategies
Selecting the best design strategy
Selecting the best design strategy for Internet applications
6.37