Systems Analysis and Design in a Changing World, 6th Edition 1

Chapter 2

Investigating System Requirements

Systems Analysis and Design in a Changing World 6th Ed

Satzinger, Jackson & Burd

Chapter 2

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Chapter 2 Outline

Systems Analysis Activities What Are Requirements? Models and Modeling Stakeholders Information-Gathering Techniques Documenting Workflows with Activity

Diagrams

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This Chapter Focuses onSystems Analysis Activities

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Systems Analysis Activities Gather Detailed Information

Interviews, questionnaires, documents, observing business processes, researching vendors, comments and suggestions

Define Requirements Modeling functional requirements and non-functional

requirements Prioritize Requirements

Essential, important, vs. nice to have Develop User-Interface Dialogs

Flow of interaction between user and system Evaluate Requirements with Users

User involvement, feedback, adapt to changes

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What Are Requirements? Defined (Webster’s third dictionary)

requirement   n  -S   : something required: a  : something that is wanted or needed: NECESSITY b  : something called for or demanded : a requisite or essential

condition : a required quality, course, or kind of training

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Different Types of Requirements System Requirements

Functional requirements Non-functional requirements

Functional Requirements– the activities the system must perform Business uses, functions the users carry out Use cases in Chapter 1

Non-Functional Requirements– other system characteristics Constraints and performance goals

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FURPS+ Requirements Acronym

Functional requirements

Usability requirements

Reliability requirements

Performance requirements

Security requirements

+ even more categories…

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FURPS+ Requirements Acronym

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Models and Modeling How do we define requirements? After collecting

information, create models Model– a representation of some aspect of the

system being built Types of Models

Textual model– something written down, described Graphical models– diagram, schematic Mathematical models– formulas, statistics, algorithms

Unified Modeling Language (UML) Standard graphical modeling symbols/terminology

used for information systems

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Some Analysis and Design Models

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Reasons for Modeling Learning from the modeling process Reducing complexity by abstraction Remembering all the details Communicating with other development team members Communicating with a variety of users and stakeholders Documenting what was done for future

maintenance/enhancement Finding/correcting areas where errors/inefficiencies

occur Modelling is not a linear process!

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StakeholdersWho do you involve and talk to? Stakeholders– persons who have an interest in the

successful implementation of the system Internal Stakeholders– persons within the organization External stakeholders – persons outside the

organization Operational stakeholders – persons who regularly

interact with the system Executive stakeholders– persons who don’t directly

interact, but use the information or have financial interest

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Stakeholders of a comprehensive accounting

system for public company

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RMO Internal Stakeholders

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Information Gathering Techniques Interviewing users and other stakeholders Distributing and collecting questionnaires Reviewing inputs, outputs, and documentation Observing and documenting business

procedures Researching vendor solutions Collecting active user comments and

suggestions

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Interviewing Users and Other Stakeholders

1. Prepare detailed questions

2. Meet with individuals or groups of users

3. Obtain and discuss answers to the questions

4. Document the answers

5. Follow up as needed in future meetings or interviews

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Themes for Information Gathering Questions

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Preparing for Interview

Other Considerations for Interviews

Target certain people “super users”

Make sure that all questions are relevant Time is money

This is a good chance to get buy-in from the user! Focus groups may be appropriate Anonymity may also be appropriate Location? Compensation? After every interview, review and change the agenda as

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Interview Session Agenda

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Keeping an Open Items List

Used if a question requires follow-up (ie it cannot be answered by an interviewee in an interview)

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Distribute and Collect Questionnaires

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Review Inputs, Outputs, and Procedures

* Blank ones or filled out ones?

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Additional Techniques

Observe and Document Business Processes Watch and learn Document with Activity diagram (next section)

Research Vendor Solutions See what others have done for similar situations White papers, vendor literature, competitors “best practices” or “common practice”

Collect Active User Comments and Suggestions Feedback on models and tests Users know it when the see it

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Documenting Workflows with Activity Diagrams

Workflow sequence of processing steps that completely handles

one business transaction or customer request Activity Diagram

describes user (or system) activities, the person who does each activity, and the sequential flow of these activities

Useful for showing a graphical model of a workflow A UML diagram

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Activity Diagram for RMO Order Fulfillment

Can be “as-is”as well as “to-be”

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Activity Diagrams Symbols

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Activity Diagram with Concurrent Paths

Questions/Discussion

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