1. Investigating System Requirements
Chapter 2

2. Where are we? Analysis Chapters Ch 2 Investigating System Requirements
Use Cases
Ch 4
Domain Modeling
Ch 5
Use Case Modeling

3. Outline
Stakeholders
SDLC Core Process 3 – Analysis – Discover & Understand Details
Information Gathering Techniques
Types of Requirements
FURPS+

4. Stakeholders - "Who do you involve and talk to?"
Internal Stakeholders
External stakeholders
Operational stakeholders
regularly interact with system
Executive stakeholders
don’t directly interact but ..
use the info , or
have financial interest

5. SDLC Phase: Analysis
Core Process 3: Discover & understand details

6. SDLC Phase: Analysis Gather detailed info
Information Gathering Techniques
Interviews
Observation
Review documents & procedures
Questionnaires
Research vendor solutions
User feedback
Why do we use different Techniques?
Formal Systems
Informal Systems

7. Information Gathering Techniques
Interviews
Interview users & other key stakeholders
Effective way to understand business functions and rules
Disadvantage
time consuming
resource expensive
Tips:
Plan the interview
Stay on schedule!!
Interview several key people together (pros & cons)
Listen carefully and take notes
Be neutral
Seek diverse views

8. Checklist for Conducting an Interview

9. Information Gathering Techniques
Observations
Direct Observation
Watching users do their jobs
Firsthand & objective
Disadvantage
People may change their normal operating behavior.
Time-consuming

10. Information Gathering Techniques
Review Documents & Procedures
Existing business documents
Forms, reports, work procedures
Input & outputs
Types of information to be discovered:
Reasons for current system design
Rules for processing data
Problems with existing system
Discrepancies, Redundancies
Opportunity to meet new need
Special information processing circumstances

11. Information Gathering Techniques
Questionnaires
Used with a large number of stakeholders
Closed-ended (Quantitative data )
Open-ended questions (Qualitative data)
Research Vendor Solutions
Many problems have been solved by other companies
+ provide new ideas, cheaper, less risky
- may purchase before understanding problem
User Feedback
Collecting feedback after initial testing
Comments & suggestions

12. SDLC Phase: Analysis
Define requirements
System Requirements - (def) specifications that define the new system
Functional Requirements - activities the system must perform
Non-Functional Requirements - constraints and performance goals
Functional Usability Reliability Performance Security requirements requirements requirements requirements requirements
Business rules & processes
UI Design
Navigation
Help Doc.
Avail. reqs
Failure rate
Backup & recovery
Response time
real time
-batch
Access controls
Encryption

13. SDLC Phase: Analysis Define requirements cont. Prioritize requirements
Create models of the requirements
Model - a representation of some aspect of a system
Textual model, Graphical models, Mathematical models
Prioritize requirements
High vs. low priority
Scope creep
Develop UI Dialogs
Prototype
Can be better than an abstract model
Evaluate Requirements with users