Systems Analysis & Design - Determining System Requirements

Determining System Requirements

Learning Objectives

Describe options for designing and conducting interviews and develop a plan for conducting an interview to determine system requirements.

Design, distribute, and analyze questionnaires to determine system requirements.

Explain advantages and pitfalls of observing workers and analyzing business documents to determine requirements.

Explain how computing can provide support for requirements determination.

Learn about Joint Application Design (JAD)

Use prototyping during requirements determination.

Select the appropriate methods to elicit system requirements.

Apply requirements determination to Internet applications.

Performing Requirements Determination

Gather information on what system should do from many sources.

Users
Reports
Forms
Procedures

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

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

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
• Interviewing (Continued)
• Interview Questions
• Open-Ended
• No pre-specified answers
• Close-Ended
• Respondent is asked to choose from a set of specified responses
• Additional Guidelines
• Do not phrase questions in ways that imply a wrong or right answer
• Listen very carefully to what is being said
• Type up notes within 48 hours
• Do not set expectations about the new system
• 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
• 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 7-4 for a complete comparison
• Interviewing Groups
• Advantages
• More effective use of time
• Enables people to hear opinions of others and to agree or disagree
• Disadvantages
• Difficulty in scheduling
• Nominal Group Technique
• Facilitated process to support idea generation by groups
• Individuals work alone to generate ideas which are pooled under guidance of a trained facilitator
• Directly Observing Users
• Serves as a good method to supplement interviews
• Often difficult to obtain unbiased data
• People often work differently when being observed

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
• Reasons for current system design
• Rules for processing data
• Four types of useful documents
• Written work procedures
• Describes how a job is performed
• Includes data and information used and created in the process of performing the job or task
• Business form
• Explicitly indicate data flow in or out of a system.
• Report
• Enables the analyst to work backwards from the report to the data that generated it
• Description of current information system

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

Joint Application Design (JAD)
Participants
-Session Leader
-Users
-Managers
-Sponsor
-Systems Analysts
-Scribe
-IS Staff
End Result
-Documentation detailing existing system
-Features of proposed system
CASE Tools During JAD
-Upper CASE tools are used
-Enables analysts to enter system models directly into CASE during the JAD session
-Screen designs and prototyping can be done during JAD and shown to users
Supporting JAD with GSS
-Group support systems (GSS) can be used to enable more participation by group members in JAD
-Members type their answers into the computer
-All members of the group see what other members have been typing

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

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

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
• 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
• 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