1. Chapter 5 Agile Development Chapter 5 Agile Development Moonzoo Kim KAIST 1

2. Ex. UP Work Products 2

3. The Manifesto for Agile Software Development 3 “We are uncovering better ways of developing software by doing it and helping others do it. Through this work we have come to value: Individuals and interactions v.s. processes and tools Working software v.s. comprehensive documentation Customer collaboration v.s. contract negotiation Responding to change v.s. over following a plan That is, while there is value in the items on the right, we value the items on the left more.” Kent Beck et al

4. What is “Agility”? Effective (rapid and adaptive) response to change Effective (rapid and adaptive) response to change Effective communication among all stakeholders Effective communication among all stakeholders Drawing the customer onto the team Drawing the customer onto the team Organizing a team so that it is in control of the work performed Organizing a team so that it is in control of the work performed Yielding … Rapid, incremental delivery of software Rapid, incremental delivery of software 4

5. An Agile Process Is driven by customer descriptions of what is required (scenarios) Is driven by customer descriptions of what is required (scenarios) Recognizes that plans are short-lived Recognizes that plans are short-lived Develops software iteratively with a heavy emphasis on construction activities Develops software iteratively with a heavy emphasis on construction activities Delivers multiple ‘software increments’ Delivers multiple ‘software increments’ Adapts as changes occur Adapts as changes occur 5

6. 12 Principles of Agile Process To satisfy the customer through early and continuous delivery of valuable SW To satisfy the customer through early and continuous delivery of valuable SW Welcome changing requirements, even late in development Welcome changing requirements, even late in development Deliver working SW frequently (from a couple of weeks to a couple of months) Deliver working SW frequently (from a couple of weeks to a couple of months) Business people and developers must work together daily Business people and developers must work together daily Build projects around motivated individuals Build projects around motivated individuals The most effetive method of communication is face-to-face conversation The most effetive method of communication is face-to-face conversation 6 Working SW is the primary measure of progress Working SW is the primary measure of progress Agile processes promote sustainable development Agile processes promote sustainable development Continuous attention to technical excellence and good design Continuous attention to technical excellence and good design Keep it simple (KIS) Keep it simple (KIS) The best architectures, requirements, and designs emerge from self- organinzing teams The best architectures, requirements, and designs emerge from self- organinzing teams At regular intervals, the team reflects on how to become more effective, then tunes and adjusts its behavior At regular intervals, the team reflects on how to become more effective, then tunes and adjusts its behavior

7. 7 Human Factors the process molds to the needs of the people and team, not the other way around the process molds to the needs of the people and team, not the other way around key traits must exist among the people on an agile team and the team itself: key traits must exist among the people on an agile team and the team itself: Competence. Competence. Common focus. Common focus. Collaboration. Collaboration. Decision-making ability. Decision-making ability. Fuzzy problem-solving ability. Fuzzy problem-solving ability. Mutual trust and respect. Mutual trust and respect. Self-organization. Self-organization.

8. Extreme Programming (XP) (1/3) The most widely used agile process, originally proposed by Kent Beck The most widely used agile process, originally proposed by Kent Beck XP Planning XP Planning Begins with the creation of “user stories” that describe required features and functionality for SW Begins with the creation of “user stories” that describe required features and functionality for SW Agile team assesses each story and assigns a cost (in weeks) Agile team assesses each story and assigns a cost (in weeks) Stories are grouped to for a deliverable increment Stories are grouped to for a deliverable increment A commitment is made on delivery date A commitment is made on delivery date After the first increment “project velocity” (# of user stories implemented during the first release) is used to help define subsequent delivery dates for other increments After the first increment “project velocity” (# of user stories implemented during the first release) is used to help define subsequent delivery dates for other increments 8

9. Extreme Programming (XP) (2/3) XP Design XP Design Follows the KIS principle Follows the KIS principle Encourage the use of CRC (class-responsibility-collaborator) cards (see Chapter 24) Encourage the use of CRC (class-responsibility-collaborator) cards (see Chapter 24) For difficult design problems, suggests the creation of a spike solution (a design prototype) For difficult design problems, suggests the creation of a spike solution (a design prototype) A spike solution is a very simple program to explore potential solutions. A spike solution is a very simple program to explore potential solutions. Encourages “refactoring”—an iterative refinement of the internal program design Encourages “refactoring”—an iterative refinement of the internal program design XP Coding XP Coding Recommends the construction of a unit test for a store before coding commences Recommends the construction of a unit test for a store before coding commences Test oriented implementation (a.k.a. TDD) Test oriented implementation (a.k.a. TDD) Encourages “pair programming” Encourages “pair programming” XP Testing XP Testing All unit tests are executed daily All unit tests are executed daily “Acceptance tests” are defined by the customer and executed to assess customer visible functionality “Acceptance tests” are defined by the customer and executed to assess customer visible functionality 9

10. Extreme Programming (XP) (3/3) 10

11. Adaptive Software Development (ASD) Originally proposed by Jim Highsmith Originally proposed by Jim Highsmith Focus on human collaboration and team self- organization Focus on human collaboration and team self- organization ASD — distinguishing features ASD — distinguishing features Component-based focus Component-based focus Explicit consideration of risks Explicit consideration of risks Emphasizes collaboration for requirements gathering Emphasizes collaboration for requirements gathering Emphasizes “learning” throughout the process Emphasizes “learning” throughout the process 11

12. Adaptive Software Development 12

13. Dynamic Systems Development Method (DSDM) Promoted by the DSDM Consortium (www.dsdm.org) Promoted by the DSDM Consortium (www.dsdm.org)www.dsdm.org DSDM—distinguishing features DSDM—distinguishing features Similar in most respects to XP and/or ASD Similar in most respects to XP and/or ASD Nine guiding principles Nine guiding principles Active user involvement is imperative. Active user involvement is imperative. DSDM teams must be empowered to make decisions. DSDM teams must be empowered to make decisions. The focus is on frequent delivery of products. The focus is on frequent delivery of products. Fitness for business purpose is the essential criterion for acceptance of deliverables. Fitness for business purpose is the essential criterion for acceptance of deliverables. Iterative and incremental development is necessary to converge on an accurate business solution. Iterative and incremental development is necessary to converge on an accurate business solution. All changes during development are reversible. All changes during development are reversible. Requirements are baselined at a high level Requirements are baselined at a high level Testing is integrated throughout the life-cycle. Testing is integrated throughout the life-cycle. 13

14. Scrum Originally proposed by Schwaber and Beedle Originally proposed by Schwaber and Beedle Scrum—distinguishing features Scrum—distinguishing features Testing and documentation are on-going as the product is constructed Testing and documentation are on-going as the product is constructed Work occurs in “sprints” and is derived from a “backlog” of existing requirements Work occurs in “sprints” and is derived from a “backlog” of existing requirements Backlog: a prioritized list of project requiremetns or features Backlog: a prioritized list of project requiremetns or features Sprint: work tasks within a process pattern Sprint: work tasks within a process pattern Daily meetings are very short and sometimes conducted without chairs Daily meetings are very short and sometimes conducted without chairs Demos are delivered to the customer within the time-box allocated Demos are delivered to the customer within the time-box allocated 14

15. Feature Driven Development (FDD) Originally proposed by Peter Coad et al Originally proposed by Peter Coad et al FDD—distinguishing features FDD—distinguishing features Emphasis is on defining “features” Emphasis is on defining “features” a feature “is a client-valued function that can be implemented in two weeks or less.” a feature “is a client-valued function that can be implemented in two weeks or less.” Users can describe features more easily Users can describe features more easily Uses a feature template Uses a feature template the a(n) the a(n) Ex. Add the product to a shopping cart Ex. Add the product to a shopping cart Ex. Sotre the shipping-information for a customer Ex. Sotre the shipping-information for a customer Feature set template Feature set template a(n) a(n) Ex. Making a product sale Ex. Making a product sale A features list is created and “plan by feature” is conducted A features list is created and “plan by feature” is conducted Design and construction merge in FDD Design and construction merge in FDD 15

16. Agile Modeling Originally proposed by Scott Ambler Originally proposed by Scott Ambler Suggests a set of agile modeling principles for building large, business critical systems Suggests a set of agile modeling principles for building large, business critical systems Model with a purpose Model with a purpose Use multiple models Use multiple models Travel light Travel light Content is more important than representation Content is more important than representation Know the models and the tools you use to create them Know the models and the tools you use to create them Adapt locally Adapt locally 16