Agile Entwicklung Technical Literacy 1

Transkript

1 Agile Entwicklung Technical Literacy 1 Prof. Dr.-Ing. Carsten Bormann 1

2 xkcd 844! Thanks, Randall Munroe, for all the wonderful teaching materials

3 !Building the thing right vs.!building the right thing

4 agilemanifesto.org!individuals and interactions over processes and tools!working software over comprehensive documentation!customer collaboration over contract negotiation!responding to change over following a plan 9

5 agilemanifesto: Principles (1)! Our highest priority is to satisfy the customer through early and continuous delivery of valuable software.! Welcome changing requirements, even late in development. Agile processes harness change for the customer's competitive advantage.! Deliver working software frequently, from a couple of weeks to a couple of months, with a preference to the shorter timescale.! Business people and developers must work together daily throughout the project. 10

6 agilemanifesto: Principles (2)! Build projects around motivated individuals. Give them the environment and support they need, and trust them to get the job done.! The most efficient and effective method of conveying information to and within a development team is faceto-face conversation.! Working software is the primary measure of progress.! Agile processes promote sustainable development.! The sponsors, developers, and users should be able to maintain a constant pace indefinitely. 11

7 agilemanifesto: Principles (3)! Continuous attention to technical excellence and good design enhances agility.! Simplicity the art of maximizing the amount of work not done is essential.! The best architectures, requirements, and designs emerge from self-organizing teams.! At regular intervals, the team reflects on how to become more effective, then tunes and adjusts its behavior accordingly. 12

8 Agile Development Agile Focus Agile Collaboration Agile Feedback Agile Debugging Agile Coding 13

9 Agile Focus! Work for outcome Customer Value pays the bills Justify Technology Use! Let Customers make Decisions Activate tacit knowledge, avoid Process Confabulation Embrace Change!! Use Short Iterations, Release in Increments Create Customer Value quickly! Get non-confabulated requirements! Fixed Prices are Broken Promises 14

10 Agile Feedback! Question until you understand! Get Frequent Feedback Using Demos! Keep it releasable Continuous Integration! Automate Acceptance Testing a feature doesn't actually exist until tests prove that it works! Use Short Iterations, Release in Increments! Feel the Rhythm 15

11 Agile Coding! Test First (Test-Driven Development) " red/green/refactor! Program Intently and Expressively (PIE! clever) clean code is code that is pretty much what you would expect! Communicate by Code comments are a code smell documents? " customer developer " developer developer " presence future use an agile language!! Keep it Simple 16

12 Agile Debugging! Quick Fixes become Quicksand! Keep Logs! Report all Exceptions crash/log on bugs be robust to environmental problems! Attack Problems in Isolation e.g., use mocks for unit testing! Test-Driven Development! Continuous Integration 17

13 Agile Collaboration! Schedule Regular Face Time Standup Meeting: Announce Yesterday/Today/Obstacles! Criticize Ideas, not People! Invest in your Team Know when to unlearn Architects Must Write Code! Practice Collective Ownership Review Code! Keep Others Informed! Teams must be sustainable 18

14 Focus: Planning Game! Iterationen, z.b. alle zwei Wochen; Inkremente! Beginn: Planning Game! Kunde: Story Cards für neue Funktionen! Entwickler: Bewerten (Story Points) ggfs aufteilen! Kunde sortiert was ist in der nächsten Iteration? begrenzt durch Anzahl Punkte weitergehende Planung möglich, bleibt flexibel! Am Ende: Abgleich Planung/Realität Selbstreflexion und Adaption! z.b.: Punktesystem anpassen (Velocity) 19

15 TDD: Test-Driven Development Test schreiben Test ausführen TDD-Zyklus Refactoring Code schreiben Test ausführen Bild: Jan Krutisch 20

16 TDD: Test-Driven Development red/green/refactor! Tests zwingen, frühzeitig über das API nachzudenken dokumentieren den Code geben Sicherheit beim Refactoring Work for Outcome: YAGNI (You Aren t Gonna Need It)! Ping-Pong paßt hervorragend zur Paarprogrammierung (Driver-/Navigator-Paradigma)! Es gibt immer noch Bugs, aber jeweils nur einmal! Continuous Integration 21

17 Essentials: Prozesse und Tools! Versionskontrolle Für alle Dokumente (Quelltext, Spezifikationen, Dokumentation)! Automatischer Build-Prozeß Continuous Integration (gute Testabdeckung!) Manuelle Prozesse vermeiden oder regelmäßig üben! Bug-Tracking Zero-Defect-Strategie! Kommunikation: F2F + Lebendige Dokumente Minimale technische/organisatorische Barrieren! Wiki! Projektmanagement, Zeitplan User Stories; voll heruntergebrochene Aktivitäten (Tasks) Embrace Change! 22