Visual Models for Software Requirements by Beatty, Joy -- Read -- Imperial Library of Trantor

Index

Visual Models for Software Requirements Dedication A Note Regarding Supplemental Files Foreword Introduction

Who Should Read This Book

Assumptions

Who Should Not Read This Book Organization of This Book

Finding Your Best Starting Point in This Book Models Quick Start

Conventions and Features in This Book Companion Content Acknowledgments Errata & Book Support We Want to Hear from You Stay in Touch

I. An Introduction to Models

1. Introduction to RML

RML Defined Challenges with Traditional Software Requirements Practices

Limitations of the Human Brain Pictures Are Easy, Words Are Hard

Requirements Models

Why Not UML? Requirements vs. Design

One Level’s Requirement Is Another Level’s Design Determining Actual Business Need Requirements Defined

Requirements Models Are Not the End Game

Using RML on Projects Additional Resources References

2. Model Categorization

Objectives, People, Systems, and Data Models

Bounding Models All Four Categories Are Needed

Objectives Models People Models Systems Models Data Models References

II. Objectives Models

3. Business Objectives Model

Business Objectives Model Template Example Creating Business Objectives Models

Identify Business Problems

Revenue Needs to Be Higher Costs Need to Be Lower Eliciting Business Problems

Identify Business Objectives Define Additional Problems and Objectives Define the Product Concept

Guiding Principles

Describe Success Metrics Questions to Ask to Complete the Business Objectives Model

Using Business Objectives Models

Providing a Common Understanding of a Project’s Value Bounding the Solution Space Understanding Projects That Are Underway

A Typical Approach That Doesn’t Work An Ideal Approach That Starts with Problems and Objectives A Realistic Approach

Deriving Requirements When to Use When Not to Use

Common Mistakes

Not Understanding the Business Problem Defining Business Objectives That Are Not Measurable Articulating the Wrong Type of Information in Business Objectives

Related Models Exercise

Instructions Scenario

Additional Resources References

4. Objective Chain

Objective Chain Template Example Creating Objective Chains

Identify Business Objectives and Features Select the Features to Analyze in Objective Chains Identify the Objective Factors

Use the Business Objectives Model Simplify Objective Factor Statements

Create the Objective Chain Hierarchy Define the Objective Equations

Format the Equation Identify Data Values Debate Data Values Measure Assumptions

Using Objective Chains

Comparing the Relative Values of Features to Cut Scope

Determining the Value of a Feature Mapped to Multiple Business Objectives Determining the Value of Multiple Features Mapped to the Same Objective Chain Determining the Value of Features Attached to Emotional Objectives

Determining Project Success Deriving Requirements When to Use When Not to Use

Common Mistakes

Not Creating Objective Chains Because Data Doesn’t Exist Skipping Levels in the Hierarchy

Related Models Exercise

Instructions Scenario

Additional Resources References

5. Key Performance Indicator Model

KPIM Template Example Creating KPIMs

Identify Business Processes

Selecting the Right Level Selecting the Right Processes

Identify KPIs Create the KPIM

Using KPIMs

Prioritizing KPIMs When Business Objectives Don’t Help Prioritizing When Replacing Existing Functionality Comparing the Relative Values of Requirements to Cut Scope Deriving Requirements When to Use When Not to Use

Common Mistakes

Not Using KPIMs Because KPIs Don’t Exist Not Using KPIMs Due to Fears of Being Held Accountable A Lack of Ongoing Monitoring

Related Models Exercise

Instructions Scenario

Additional Resources

6. Feature Tree

Feature Tree Template Example Creating Feature Trees

Identify Features Organize the Features

Subfeatures of More Than One Feature Parentless Subfeatures

Create the Feature Tree Look for Missing Features

Using Feature Trees

Depicting Project Scope Organizing the Requirements Organizing the Requirements Work Deriving Requirements When to Use When Not to Use

Common Mistakes

Wrong Number of Features at Each Level Poor Feature Names

Related Models Exercise

Instructions Scenario

Additional Resources References

7. Requirements Mapping Matrix

RMM Template Example Creating RMMs

List Process Flow Steps Map Requirements to Process Flow Steps

Many-to-Many Mappings Different Ways to Map Business Rules Using a Tool to Create Mappings

Identify Missing Mappings

Using RMMs

Reviewing in an Easy-to-Read Structure Identifying Missing Requirements Identifying Extraneous Requirements or Missing Steps Prioritizing Scope Advantages of Using a Requirements Management Tool Deriving Requirements When to Use When Not to Use

Common Mistakes

Not Mapping to Process Flows Not Using or Updating RMMs

Related Models Exercise

Instructions Scenario

Additional Resources References

III. People Models

8. Org Chart

Org Chart Template Example Creating Org Charts

Locate Existing Org Charts Determine the Right Level of Org Chart Complete the Org Chart

Departmental Org Charts Role Org Charts Individual Org Charts

Using Org Charts

Identifying the People Who Have Requirements Identifying Internal Users Identifying External Users Identifying People Used in Other Models Using Org Charts with Process Flows for Completeness Deriving Requirements When to Use When Not to Use

Common Mistakes

Not Using Org Charts to Identify Stakeholders Only Including Project Team Members

Related Models Exercise

Instructions Scenario

Additional Resources References

9. Process Flow

Process Flow Template Example Creating Process Flows

Create an L1 Process Flow

Creating the Diagram Scope of an L1

Create L2 Process Flows

Identifying Process Steps Writing Steps Using Swim Lanes Adding References to Other Flows Using Additional Symbols

Create L3 Process Flows As Necessary

Using Process Flows

Targeting the Audience with Different Levels of Detail Running Elicitation and Review Sessions Driving Completeness Deriving Requirements When to Use When Not to Use

Common Mistakes

Level of Detail Is Inconsistent Within a Flow Reviewers Do Not Understand the Level of Detail Reviewers Forget to Look at the Full Process Flow Process Flow Has Too Many Steps System Responses Are Mixed with User Actions Processes Outside the Scope of the Project Are Not Included

Related Models Exercise

Instructions Scenario

Additional Resources References

10. Use Case

Use Case Template Example Creating Use Cases

Identify Use Cases

From Process Flows From Business Data Diagrams From Org Charts or Lists of Actors

Write Descriptions Capture Organizational Benefits Capture Frequency of Use Prioritize Use Cases Complete the Remaining Header Fields

Assign a Unique ID Identify Actors Identify Triggers Identify Preconditions Identify Postconditions

Write the Main Course Write the Alternate Courses Write the Exceptions

Using Use Cases

Providing Context for Elicitation Through Implementation Prioritizing Work Deriving Requirements Reusing Use Cases Using a Use Case as a Basis for a UAT Script Using Models Similar to Use Cases Use Cases Do Not Have to Be Perfect When to Use When Not to Use

Common Mistakes

Making Use Cases Too Granular Using Use Cases As the Only Documentation for Requirements Allowing the System to Be an Actor

Related Models Exercise

Instructions Scenario

Additional Resources References

11. Roles and Permissions Matrix

Roles and Permissions Matrix Template Example Creating Roles and Permissions Matrices

Identify the Roles Identify the Operations Indicate Permissions

Permissions by Operation Permissions on Scope of Data Common Permissions on Related Operations

A Word About When to Create the Matrix

Using Roles and Permissions Matrices

Deriving Requirements Driving Completeness Identifying Additional Functions Configuring Systems Using a Roles and Permissions Matrix As a Basis for Setting Up User Data for Deployment When to Use When Not to Use

Common Mistakes

Missing Operations Struggling to Organize the Roles

Related Models Exercise

Instructions Scenario

Additional Resources

IV. Systems Models

12. Ecosystem Map

Ecosystem Map Template Example Creating Ecosystem Maps

Identify Systems Identify Interfaces Tie the Diagram Together

Using Ecosystem Maps

Defining Scope with Ecosystem Maps Deriving Requirements When to Use When Not to Use

Common Mistakes

Showing Physical Systems Too Much Documentation Lack of Organization

Related Models Exercise

Instructions Scenario

Additional Resources References

13. System Flow

System Flow Template Example Creating System Flows

Identify System Steps

Feature Trees Data Flow Diagrams

Write Steps

Swim Lanes Events

Using System Flows

Running System Flows Parallel to Process Flows Deriving Requirements When to Use

Describing Hidden Activities Describing System Interactions Describing Exception Handling

When Not to Use

Common Mistakes Related Models Exercise

Instructions Scenario

Additional Resources

14. User Interface Flow

UI Flow Template Example Creating UI Flows

Determine Scope of Screens Identify Screens

Diagramming What Constitutes a Screen?

Create Transitions

Identifying the Transitions Adding Transitions to the Diagram Branching

Label Triggers

Using UI Flows

Identifying Navigation Validating Navigation Optimizing Usability Developing Test Cases Deriving Requirements When to Use When Not to Use

Common Mistakes

Including Too Much Detail Including Unimportant Details Not Using a UI Expert When Needed

Related Models Exercise

Instructions Scenario

Additional Resources Rferences

15. Display-Action-Response

DAR Model Template

UI Element Description UI Element Displays UI Element Behaviors

Example Creating DAR Models

Prepare the Screen Create a UI Element Description Create the UI Element Displays Section Create the UI Element Behaviors Section Guidelines for Creating Element Tables

Using DARs

Driving Completeness Deriving Requirements When to Use When Not to Use

Common Mistakes

Modeling Too Much Modeling Elements with No Data-Driven Behavior or Display Using Only UI-Based Models or Prototypes Focusing on the User Interface Too Early Including Too Much Fidelity in the Screen Layout

Related Models Exercise

Instructions Scenario

Additional Resources References

16. Decision Table

Decision Table Template Example Creating Decision Tables

Identify Conditions Identify Choices

Determining Valid Choices Reordering Conditions Enumerating Choices

Identify Outcomes Label Valid Outcomes by Choice Combinations Simplify the Decision Table

Using Decision Tables

Making Decisions Driving Completeness Using Decision Tables with Decision Trees Deriving Requirements When to Use

Modeling Complex Logic

When Not to Use

Common Mistakes

Missing Permutations Overlapping Choice Ranges Not Combining Rules Modeling a Sequence of Decisions

Related Models Exercise

Instructions Scenario

Additional Resources References

17. Decision Tree

Decision Tree Template Example Creating Decision Trees

Identify Decisions Identify Choices Identify Outcomes Repeat Until Every Branch Ends in an Outcome Simplify the Decision Tree

Using Decision Trees

Driving Completeness Simplifying Logic Modeling Nested “If” Statements Training Users Deriving Requirements When to Use

Ordering Looping

When Not to Use

Common Mistakes

Modeling Process Steps Making All Yes or No Choices

Related Models Exercise

Instructions Scenario

Additional Resources References

18. System Interface Table

System Interface Table Template Example Creating System Interface Tables

Identify System Interfaces Determine Business Data Objects and Fields Determine Frequency of Transfer Determine Volume of Data Determine Error Handling Determine Security Constraints

Using System Interface Tables

Deriving Requirements When to Use When Not to Use

Common Mistakes

Including Information That Is Too Technical Documenting Every Interface Not Understanding User Needs

Related Models Exercise

Instructions Scenario

V. Data Models

19. Business Data Diagram

BDD Template

Business Data Example Diagram Template

Example Creating BDDs

Identify Business Data Objects Relate Business Data Objects Add Cardinalities Creating Business Data Example Diagrams

Using BDDs

Understanding the High-Level Business Data Objects Driving Completeness Identifying Processes Helping Technical Teams with Database Design Using Business Data Example Diagrams to Review BDDs Deriving Requirements When to Use When Not to Use

Common Mistakes

Including Fields As Objects Creating Middle-Man Objects Thinking in Terms of a Database Design

Related Models Exercise

Instructions Scenario

Additional Resources References

20. Data Flow Diagram

DFD Template Example Creating DFDs

Identify Business Data Objects Identify Processes Identify External Entities Tie the Diagram Together

Using DFDs

Representing Data Used Across Multiple Processes Using DFDs to Help with Readability Driving Completeness Deriving Requirements When to Use When Not to Use

Common Mistakes

Trying to Articulate Order in a DFD Trying to Document Every Single Data Flow

Related Models Exercise

Instructions Scenario

Additional Resources References

21. Data Dictionary

Data Dictionary Template

Properties List

Example Creating Data Dictionaries

Tailor Properties Identify Business Data Objects and Fields Populate Properties Supplement with Data Catalogs

Using Data Dictionaries

Promoting a Consistent Data Nomenclature Driving Completeness Deriving Requirements When to Use When Not to Use

Common Mistakes

Becoming Overwhelmed by the Size Not Articulating Important Validation Rules

Related Models Exercise

Instructions Scenario

Additional Resources References

22. State Table

State Table Template Example Creating State Tables

Identify the Business Data Objects Identify the States Analyze the Transitions

Using State Tables

Enhancing Readability Driving Completeness

Completing Other Models

Deriving Requirements When to Use When Not to Use

Common Mistakes

States That Are Not States Missing States Incorrect “No” Transitions

Related Models Exercise

Instructions Scenario

Additional Resources References

23. State Diagram

State Diagram Template Example Creating State Diagrams

Identify the Business Data Objects Identify the States Analyze the Transitions

Using State Diagrams

Visualizing Flow Between States Driving Completeness Deriving Requirements When to Use When Not to Use

Common Mistakes

States That Are Not States Missing States and Transitions

Related Models Exercise

Instructions Scenario

Additional Resources References

24. Report Table

Report Table Template Example Creating Report Tables

Identify Reports Prioritize Reports Complete Report Table Elements

Report Table Top-Level Elements Report Table Field Elements Managing Report Scope

Using Report Tables

Defining the Reports Checking Completeness and Consistency Against Other Models Deriving Requirements When to Use When Not to Use

Common Mistakes

Not Relating Reports to Decisions Made Documenting Unnecessary Reports

Related Models Exercise

Instructions Scenario

VI. Models in the Big Picture

25. Selecting Models for a Project

Selecting Models by Project Phases

Envision Phase Plan Phase Develop Phase Launch Phase Measure Phase

Selecting Models by Project Characteristics

Objectives Characteristics

Greenfield Projects Commercial Off the Shelf (COTS) Projects Enhancement Projects

People Characteristics

Systems with Extensive User Interaction Customer-Facing Systems Business Process Automation Projects Workflow Automation Projects

Systems Characteristics

System Replacement Projects Real-Time and Embedded Systems Large-Ecosystem Projects Internal IT Systems Hardware and Software Packaged Software Cloud Implementation Projects Web App Projects Mobile Systems Projects with Complex Decision Logic

Data Characteristics

Analytics and Reporting Components Database Back-End Components Data Warehouse Components

Project Examples

Thinking About the Audience Tailoring Models Exercise

Instructions Scenario

26. Using Models Together

Many Different Views Using More Than One Model Requirements Architecture

Relationships Between Models Where the Artifacts Live

A Models Plan Related Models Exercise

Instructions Scenario

A. Quick Lookup Models Grids

Additional Resources

B. General Guidelines for Models

Metadata to Include in Models General Guidelines and Tips

C. Exercise Answers

Chapter 3 Chapter 4 Chapter 5 Chapter 6 Chapter 7 Chapter 8 Chapter 9 Chapter 10 Chapter 11 Chapter 12 Chapter 13 Chapter 14 Chapter 15 Chapter 16 Chapter 17 Chapter 18 Chapter 19 Chapter 20 Chapter 21 Chapter 22 Chapter 23 Chapter 24 Chapter 25 Chapter 26

Glossary Index About the Authors Copyright

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