SlideShare une entreprise Scribd logo
1  sur  54
What is Scrum? This Stack is based upon the Redistributable Scrum Introduction Stack from the Scrum Alliance This work is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike License Richard Fennell Engineering Director, Black Marble Ltd.
Origins of Scrum ,[object Object],[object Object],[object Object],[object Object]
Origins of Scrum ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
Scrum has been used in… ,[object Object],[object Object],[object Object],[object Object],[object Object]
Scrum has been used for… Commercial software In-house development Contract development Fixed-price projects Financial applications ISO 9001-certified applications Embedded systems 24x7 systems with 99.999% uptime requirements The Joint Strike Fighter Video game development FDA-approved, life-critical systems Satellite-control software Websites Handheld software Mobile phones Network switching applications ISV applications Some of the largest applications in use
Characteristics ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
The Agile Manifesto a statement of values Source: www.agilemanifesto.org Process and tools Individuals and interactions over Following a plan Responding to change over Comprehensive documentation Working software over Contract negotiation Customer collaboration over
Project Noise Level Complex Close to Certainty Far from Certainty Technology Close to Agreement Far from Agreement Requirements Source:  Strategic Management and Organizational Dynamics  by Ralph Stacey   in  Agile Software Development with Scrum  by Ken Schwaber and Mike Beedle.
Scrum Process Overview 10 - 30 days 24 hours Product Backlog As prioritized by Product Owner Sprint Backlog Backlog tasks expanded by team Potentially Shippable Product Increment Daily Scrum Meeting Source: Adapted from  Agile Software Development with Scrum  by Ken Schwaber and Mike Beedle.
Sprints ,[object Object],[object Object],[object Object],[object Object],[object Object]
Sequential vs. overlapping development Source: “The New New Product Development Game” by Takeuchi and Nonaka.  Harvard Business Review,  January 1986. Rather than doing all of one thing at a time... ...Scrum teams do a little of everything all the time Requirements Design Code Test
No changes during a sprint ,[object Object],Change
Scrum framework ,[object Object],[object Object],[object Object],Roles ,[object Object],[object Object],[object Object],[object Object],Ceremonies ,[object Object],[object Object],[object Object],Artifacts
Scrum framework ,[object Object],[object Object],[object Object],Artifacts ,[object Object],[object Object],[object Object],[object Object],Ceremonies ,[object Object],[object Object],[object Object],Roles
Product owner ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
The ScrumMaster ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
The team ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
story A chicken and a pig are.... …  together when the chicken says, "Let's start a restaurant!". The pig thinks it over and says, "What would we call this restaurant?". The chicken says, "Ham n' Eggs!". The pig says, "No thanks, I'd be committed, but you'd only be involved!".  This is the ethos for a Scum team, they are pigs, their neck is on the line in what they have committed to doing. Everyone else is a Chicken, they might be interested in the project but their job is not on the line
Scrum framework ,[object Object],[object Object],[object Object],Roles ,[object Object],[object Object],[object Object],Artifacts ,[object Object],[object Object],[object Object],[object Object],Ceremonies
Sprint planning meeting Business conditions Team capacity Product backlog Technology Current product Product owner Scrum team Customers Managmt Sprint prioritization ,[object Object],[object Object],Sprint planning ,[object Object],[object Object],[object Object],Sprint goal Sprint backlog
Sprint planning ,[object Object],[object Object],[object Object],[object Object],[object Object],As a  vacation planner ,  I want to  see photos of the hotels  so I can  have a better idea of facilities Priority 4 [10 Story Points] Code the middle tier (8 hours) Code the user interface (4) Write test fixtures (4) Code the foo class (6) Update performance tests (4)
The daily scrum ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
Everyone answers 3 questions ,[object Object],[object Object],What did you do yesterday? 1 What will you do today? 2 Is anything in your way? 3
The sprint review ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
Sprint retrospective ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
Start / Stop / Continue ,[object Object],Start doing Stop doing Continue doing This is just one of many ways to do a sprint retrospective.
Scrum framework ,[object Object],[object Object],[object Object],Roles ,[object Object],[object Object],[object Object],[object Object],Ceremonies ,[object Object],[object Object],[object Object],Artifacts
Product backlog ,[object Object],[object Object],[object Object],[object Object],[object Object],This is the product backlog
A sample product backlog Priority Backlog item Story Point Estimate 1 Allow a guest to make a reservation 3 2 As a guest, I want to cancel a reservation. 5 3 As a guest, I want to change the dates of a reservation. 3 4 As a hotel employee, I can run RevPAR reports (revenue-per-available-room) 8 5 Improve exception handling 8 6 ... 30
The sprint goal ,[object Object],Database Application Financial services Life Sciences Support features necessary for population genetics studies. Support more technical indicators than company ABC with real-time, streaming data. Make the application run on SQL Server in addition to Oracle.
Managing the sprint backlog ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
A sprint backlog Tasks Code the user interface Code the middle tier Test the middle tier Write online help Write the foo class Mon Tues Wed Thur Fri
A sprint burndown chart Hours
Hours 40 30 20 10 0 Mon Tue Wed Thu Fri Tasks Code the user interface Code the middle tier Test the middle tier Write online help Mon 8 16 8 12 Tues Wed Thur Fri 50
Team Velocity ,[object Object],[object Object],[object Object]
Scalability ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
Scaling through the Scrum of scrums
Scrum of scrums of scrums
Tools for Scrum ,[object Object],[object Object],Image Source: http://www.crisp.se/henrik.kniberg/ScrumAndXpFromTheTrenches.pdf
Tools for Scrum ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
Scrum and TFS ,[object Object],[object Object],[object Object],[object Object]
demo eScrum
 
 
 
 
 
 
 
[object Object],[object Object],[object Object],[object Object],Scrum in 100 words
Where to go next ,[object Object],[object Object],[object Object],[object Object]
A Scrum reading list ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
For Further Information ,[object Object],[object Object],[object Object],[object Object],[object Object]
Copyright notice ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Contenu connexe

Tendances

Agile Methodology(SCRUM)
Agile Methodology(SCRUM)Agile Methodology(SCRUM)
Agile Methodology(SCRUM)
KhushSlideShare
 

Tendances (20)

Scrum 101
Scrum 101Scrum 101
Scrum 101
 
Agile Scrum Overview
Agile  Scrum  OverviewAgile  Scrum  Overview
Agile Scrum Overview
 
Introduction to Scrum - Agile Methods
Introduction to Scrum - Agile MethodsIntroduction to Scrum - Agile Methods
Introduction to Scrum - Agile Methods
 
Scrum
ScrumScrum
Scrum
 
Agile Scrum software methodology
Agile Scrum software methodologyAgile Scrum software methodology
Agile Scrum software methodology
 
Introducing scrum
Introducing scrumIntroducing scrum
Introducing scrum
 
Agile Scrum Training Process
Agile Scrum Training ProcessAgile Scrum Training Process
Agile Scrum Training Process
 
Agile scrum introduction
Agile scrum introductionAgile scrum introduction
Agile scrum introduction
 
Scrum guide presentation (Scrum Guide in easy to read PPT format)
Scrum guide presentation (Scrum Guide in easy to read PPT format)Scrum guide presentation (Scrum Guide in easy to read PPT format)
Scrum guide presentation (Scrum Guide in easy to read PPT format)
 
Scrum in a nutshell
Scrum in a nutshellScrum in a nutshell
Scrum in a nutshell
 
Managing Scope Time Cost And Team In Agile
Managing Scope Time Cost And Team In AgileManaging Scope Time Cost And Team In Agile
Managing Scope Time Cost And Team In Agile
 
Scrum in 15 Minutes
Scrum in 15 MinutesScrum in 15 Minutes
Scrum in 15 Minutes
 
Introduction to Agile & Scrum
Introduction to Agile & ScrumIntroduction to Agile & Scrum
Introduction to Agile & Scrum
 
Introduction to Scrum
Introduction to ScrumIntroduction to Scrum
Introduction to Scrum
 
Scrum methodology in practice
Scrum methodology in practiceScrum methodology in practice
Scrum methodology in practice
 
Agile scrum training
Agile scrum trainingAgile scrum training
Agile scrum training
 
Scrum in an hour
Scrum in an hourScrum in an hour
Scrum in an hour
 
Scrum 101
Scrum 101 Scrum 101
Scrum 101
 
What Is Agile Scrum
What Is Agile ScrumWhat Is Agile Scrum
What Is Agile Scrum
 
Agile Methodology(SCRUM)
Agile Methodology(SCRUM)Agile Methodology(SCRUM)
Agile Methodology(SCRUM)
 

En vedette

Scrum process powerpoint ppt slides.
Scrum process powerpoint ppt slides.Scrum process powerpoint ppt slides.
Scrum process powerpoint ppt slides.
SlideTeam.net
 

En vedette (20)

Introduction To Scrum
Introduction To ScrumIntroduction To Scrum
Introduction To Scrum
 
Scrum process powerpoint ppt slides.
Scrum process powerpoint ppt slides.Scrum process powerpoint ppt slides.
Scrum process powerpoint ppt slides.
 
Scrum introduction
Scrum introductionScrum introduction
Scrum introduction
 
PSM-Professional Scrum Master-Lesson-01
PSM-Professional Scrum Master-Lesson-01PSM-Professional Scrum Master-Lesson-01
PSM-Professional Scrum Master-Lesson-01
 
PRINCE2 Agile Guidance Preview
PRINCE2 Agile Guidance PreviewPRINCE2 Agile Guidance Preview
PRINCE2 Agile Guidance Preview
 
AgileBA® - Agile Business Analysis - Foundation
AgileBA® - Agile Business Analysis - FoundationAgileBA® - Agile Business Analysis - Foundation
AgileBA® - Agile Business Analysis - Foundation
 
Professional Scrum Master I (PSM-I)
Professional Scrum Master I (PSM-I)Professional Scrum Master I (PSM-I)
Professional Scrum Master I (PSM-I)
 
Scrum
ScrumScrum
Scrum
 
Introduction To Scrum
Introduction To ScrumIntroduction To Scrum
Introduction To Scrum
 
(Re)Distribution Des Revenus FéV 2009 DéF
(Re)Distribution Des Revenus FéV 2009 DéF(Re)Distribution Des Revenus FéV 2009 DéF
(Re)Distribution Des Revenus FéV 2009 DéF
 
20081117 Bq Rationale Marketingx.0
20081117 Bq Rationale Marketingx.020081117 Bq Rationale Marketingx.0
20081117 Bq Rationale Marketingx.0
 
Agile scrum introduction
Agile scrum introductionAgile scrum introduction
Agile scrum introduction
 
Getting Product management going again with scrum
Getting Product management going again with scrumGetting Product management going again with scrum
Getting Product management going again with scrum
 
Introduction to Scrum
Introduction to ScrumIntroduction to Scrum
Introduction to Scrum
 
Market share figures of main e-commerce platforms
Market share figures of main e-commerce platformsMarket share figures of main e-commerce platforms
Market share figures of main e-commerce platforms
 
Introduction to Scrum: A How-To Guide
Introduction to Scrum: A How-To GuideIntroduction to Scrum: A How-To Guide
Introduction to Scrum: A How-To Guide
 
CS Forum 2013
CS Forum 2013CS Forum 2013
CS Forum 2013
 
Introduction to scrum
Introduction to scrumIntroduction to scrum
Introduction to scrum
 
TDD In Practice
TDD In PracticeTDD In Practice
TDD In Practice
 
In search of better velocity metrics
In search of better velocity metricsIn search of better velocity metrics
In search of better velocity metrics
 

Similaire à Black Marble Introduction To Scrum

Redistributable Intro To Scrum
Redistributable Intro To ScrumRedistributable Intro To Scrum
Redistributable Intro To Scrum
Erwin Verweij
 
Scrum Primer
Scrum PrimerScrum Primer
Scrum Primer
davelucey
 
Dot+Net+2010+Features
Dot+Net+2010+FeaturesDot+Net+2010+Features
Dot+Net+2010+Features
gurbaxrawat
 
Introduction to Scrum
Introduction to ScrumIntroduction to Scrum
Introduction to Scrum
timmcowan
 
Agile Scrum - Overview
Agile Scrum - OverviewAgile Scrum - Overview
Agile Scrum - Overview
Madan Upadhyay
 
Ssw forte-agile-seminar
Ssw forte-agile-seminarSsw forte-agile-seminar
Ssw forte-agile-seminar
SSW
 
Agile Scrum Presentation-Detailed
Agile Scrum Presentation-DetailedAgile Scrum Presentation-Detailed
Agile Scrum Presentation-Detailed
Prashaanth T R
 

Similaire à Black Marble Introduction To Scrum (20)

Intro To Scrum
Intro To ScrumIntro To Scrum
Intro To Scrum
 
Redistributable Intro To Scrum
Redistributable Intro To ScrumRedistributable Intro To Scrum
Redistributable Intro To Scrum
 
An Introduction to Scrum
An Introduction to ScrumAn Introduction to Scrum
An Introduction to Scrum
 
Scrum Primer
Scrum PrimerScrum Primer
Scrum Primer
 
Presentation: "Agile methodologies for Project Management - SCRUM" by Varty K...
Presentation: "Agile methodologies for Project Management - SCRUM" by Varty K...Presentation: "Agile methodologies for Project Management - SCRUM" by Varty K...
Presentation: "Agile methodologies for Project Management - SCRUM" by Varty K...
 
Agile Scrum Methodology
Agile Scrum MethodologyAgile Scrum Methodology
Agile Scrum Methodology
 
Agile
Agile Agile
Agile
 
Dot+Net+2010+Features
Dot+Net+2010+FeaturesDot+Net+2010+Features
Dot+Net+2010+Features
 
Agile
AgileAgile
Agile
 
Introduction to Scrum
Introduction to ScrumIntroduction to Scrum
Introduction to Scrum
 
Introduction to agile
Introduction to agileIntroduction to agile
Introduction to agile
 
Close to agile
Close to agileClose to agile
Close to agile
 
Agile Scrum - Overview
Agile Scrum - OverviewAgile Scrum - Overview
Agile Scrum - Overview
 
Ssw forte-agile-seminar
Ssw forte-agile-seminarSsw forte-agile-seminar
Ssw forte-agile-seminar
 
Agile Scrum Presentation-Detailed
Agile Scrum Presentation-DetailedAgile Scrum Presentation-Detailed
Agile Scrum Presentation-Detailed
 
English redistributable-intro-scrum
English redistributable-intro-scrumEnglish redistributable-intro-scrum
English redistributable-intro-scrum
 
Agile
AgileAgile
Agile
 
Agile Development with Scrum.pptx
Agile Development with Scrum.pptxAgile Development with Scrum.pptx
Agile Development with Scrum.pptx
 
Agile scrum induction
Agile scrum inductionAgile scrum induction
Agile scrum induction
 
Scrum Overview
Scrum OverviewScrum Overview
Scrum Overview
 

Dernier

Histor y of HAM Radio presentation slide
Histor y of HAM Radio presentation slideHistor y of HAM Radio presentation slide
Histor y of HAM Radio presentation slide
vu2urc
 
Artificial Intelligence: Facts and Myths
Artificial Intelligence: Facts and MythsArtificial Intelligence: Facts and Myths
Artificial Intelligence: Facts and Myths
Joaquim Jorge
 

Dernier (20)

Understanding Discord NSFW Servers A Guide for Responsible Users.pdf
Understanding Discord NSFW Servers A Guide for Responsible Users.pdfUnderstanding Discord NSFW Servers A Guide for Responsible Users.pdf
Understanding Discord NSFW Servers A Guide for Responsible Users.pdf
 
ProductAnonymous-April2024-WinProductDiscovery-MelissaKlemke
ProductAnonymous-April2024-WinProductDiscovery-MelissaKlemkeProductAnonymous-April2024-WinProductDiscovery-MelissaKlemke
ProductAnonymous-April2024-WinProductDiscovery-MelissaKlemke
 
Apidays New York 2024 - Scaling API-first by Ian Reasor and Radu Cotescu, Adobe
Apidays New York 2024 - Scaling API-first by Ian Reasor and Radu Cotescu, AdobeApidays New York 2024 - Scaling API-first by Ian Reasor and Radu Cotescu, Adobe
Apidays New York 2024 - Scaling API-first by Ian Reasor and Radu Cotescu, Adobe
 
Automating Google Workspace (GWS) & more with Apps Script
Automating Google Workspace (GWS) & more with Apps ScriptAutomating Google Workspace (GWS) & more with Apps Script
Automating Google Workspace (GWS) & more with Apps Script
 
A Year of the Servo Reboot: Where Are We Now?
A Year of the Servo Reboot: Where Are We Now?A Year of the Servo Reboot: Where Are We Now?
A Year of the Servo Reboot: Where Are We Now?
 
Histor y of HAM Radio presentation slide
Histor y of HAM Radio presentation slideHistor y of HAM Radio presentation slide
Histor y of HAM Radio presentation slide
 
Boost PC performance: How more available memory can improve productivity
Boost PC performance: How more available memory can improve productivityBoost PC performance: How more available memory can improve productivity
Boost PC performance: How more available memory can improve productivity
 
Partners Life - Insurer Innovation Award 2024
Partners Life - Insurer Innovation Award 2024Partners Life - Insurer Innovation Award 2024
Partners Life - Insurer Innovation Award 2024
 
HTML Injection Attacks: Impact and Mitigation Strategies
HTML Injection Attacks: Impact and Mitigation StrategiesHTML Injection Attacks: Impact and Mitigation Strategies
HTML Injection Attacks: Impact and Mitigation Strategies
 
How to Troubleshoot Apps for the Modern Connected Worker
How to Troubleshoot Apps for the Modern Connected WorkerHow to Troubleshoot Apps for the Modern Connected Worker
How to Troubleshoot Apps for the Modern Connected Worker
 
Strategies for Landing an Oracle DBA Job as a Fresher
Strategies for Landing an Oracle DBA Job as a FresherStrategies for Landing an Oracle DBA Job as a Fresher
Strategies for Landing an Oracle DBA Job as a Fresher
 
presentation ICT roal in 21st century education
presentation ICT roal in 21st century educationpresentation ICT roal in 21st century education
presentation ICT roal in 21st century education
 
Real Time Object Detection Using Open CV
Real Time Object Detection Using Open CVReal Time Object Detection Using Open CV
Real Time Object Detection Using Open CV
 
Powerful Google developer tools for immediate impact! (2023-24 C)
Powerful Google developer tools for immediate impact! (2023-24 C)Powerful Google developer tools for immediate impact! (2023-24 C)
Powerful Google developer tools for immediate impact! (2023-24 C)
 
Exploring the Future Potential of AI-Enabled Smartphone Processors
Exploring the Future Potential of AI-Enabled Smartphone ProcessorsExploring the Future Potential of AI-Enabled Smartphone Processors
Exploring the Future Potential of AI-Enabled Smartphone Processors
 
Developing An App To Navigate The Roads of Brazil
Developing An App To Navigate The Roads of BrazilDeveloping An App To Navigate The Roads of Brazil
Developing An App To Navigate The Roads of Brazil
 
Driving Behavioral Change for Information Management through Data-Driven Gree...
Driving Behavioral Change for Information Management through Data-Driven Gree...Driving Behavioral Change for Information Management through Data-Driven Gree...
Driving Behavioral Change for Information Management through Data-Driven Gree...
 
Artificial Intelligence: Facts and Myths
Artificial Intelligence: Facts and MythsArtificial Intelligence: Facts and Myths
Artificial Intelligence: Facts and Myths
 
GenCyber Cyber Security Day Presentation
GenCyber Cyber Security Day PresentationGenCyber Cyber Security Day Presentation
GenCyber Cyber Security Day Presentation
 
[2024]Digital Global Overview Report 2024 Meltwater.pdf
[2024]Digital Global Overview Report 2024 Meltwater.pdf[2024]Digital Global Overview Report 2024 Meltwater.pdf
[2024]Digital Global Overview Report 2024 Meltwater.pdf
 

Black Marble Introduction To Scrum

  • 1. What is Scrum? This Stack is based upon the Redistributable Scrum Introduction Stack from the Scrum Alliance This work is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike License Richard Fennell Engineering Director, Black Marble Ltd.
  • 2.
  • 3.
  • 4.
  • 5. Scrum has been used for… Commercial software In-house development Contract development Fixed-price projects Financial applications ISO 9001-certified applications Embedded systems 24x7 systems with 99.999% uptime requirements The Joint Strike Fighter Video game development FDA-approved, life-critical systems Satellite-control software Websites Handheld software Mobile phones Network switching applications ISV applications Some of the largest applications in use
  • 6.
  • 7. The Agile Manifesto a statement of values Source: www.agilemanifesto.org Process and tools Individuals and interactions over Following a plan Responding to change over Comprehensive documentation Working software over Contract negotiation Customer collaboration over
  • 8. Project Noise Level Complex Close to Certainty Far from Certainty Technology Close to Agreement Far from Agreement Requirements Source: Strategic Management and Organizational Dynamics by Ralph Stacey in Agile Software Development with Scrum by Ken Schwaber and Mike Beedle.
  • 9. Scrum Process Overview 10 - 30 days 24 hours Product Backlog As prioritized by Product Owner Sprint Backlog Backlog tasks expanded by team Potentially Shippable Product Increment Daily Scrum Meeting Source: Adapted from Agile Software Development with Scrum by Ken Schwaber and Mike Beedle.
  • 10.
  • 11. Sequential vs. overlapping development Source: “The New New Product Development Game” by Takeuchi and Nonaka. Harvard Business Review, January 1986. Rather than doing all of one thing at a time... ...Scrum teams do a little of everything all the time Requirements Design Code Test
  • 12.
  • 13.
  • 14.
  • 15.
  • 16.
  • 17.
  • 18. story A chicken and a pig are.... … together when the chicken says, "Let's start a restaurant!". The pig thinks it over and says, "What would we call this restaurant?". The chicken says, "Ham n' Eggs!". The pig says, "No thanks, I'd be committed, but you'd only be involved!". This is the ethos for a Scum team, they are pigs, their neck is on the line in what they have committed to doing. Everyone else is a Chicken, they might be interested in the project but their job is not on the line
  • 19.
  • 20.
  • 21.
  • 22.
  • 23.
  • 24.
  • 25.
  • 26.
  • 27.
  • 28.
  • 29. A sample product backlog Priority Backlog item Story Point Estimate 1 Allow a guest to make a reservation 3 2 As a guest, I want to cancel a reservation. 5 3 As a guest, I want to change the dates of a reservation. 3 4 As a hotel employee, I can run RevPAR reports (revenue-per-available-room) 8 5 Improve exception handling 8 6 ... 30
  • 30.
  • 31.
  • 32. A sprint backlog Tasks Code the user interface Code the middle tier Test the middle tier Write online help Write the foo class Mon Tues Wed Thur Fri
  • 33. A sprint burndown chart Hours
  • 34. Hours 40 30 20 10 0 Mon Tue Wed Thu Fri Tasks Code the user interface Code the middle tier Test the middle tier Write online help Mon 8 16 8 12 Tues Wed Thur Fri 50
  • 35.
  • 36.
  • 37. Scaling through the Scrum of scrums
  • 38. Scrum of scrums of scrums
  • 39.
  • 40.
  • 41.
  • 43.  
  • 44.  
  • 45.  
  • 46.  
  • 47.  
  • 48.  
  • 49.  
  • 50.
  • 51.
  • 52.
  • 53.
  • 54.

Notes de l'éditeur

  1. The source version of most of this stack is not from the Scrum Alliance site, but from a slightly modified one from M ike Cohn @ www.mountaingoatsoftware.com a Scrum Certified trainer The cartoon characters are copyright Black Marble Ltd