Architecture in Agile

Transcription

1 Architecture in Agile Michael Hall Three Beacons

2 Architecture The set of significant decisions about the organization of a software system, the selection of the structural elements and their interfaces by which the system is composed together with their behavior as specified in the collaboration among those elements, the composition of these elements into progressively larger subsystems, the architectural style that guides this organization, these elements and their interfaces, their collaborations, and their composition. Software architecture is concerned with not only structure and behavior but also usage, functionality, performance, resilience, reuse, comprehensibility, economic and technological constraints and trade-offs, and aesthetics. - Rational Unified Process 2

3 Architects Make major hardware/software decisions Develop proof of concepts Establish the important design patterns to follow Identify opportunities for component or service reuse Document vision Outline the quality attributes and trade-offs Establish communication channels with stakeholders* 3

4 Traditional vs. Agile Architecture 4

5 Traditional Architecture Document driven Complete big design up front (BDUF) Key decisions made up front Enforcement Relationship with Dev team Not so involved in development Hands-off the final solution Applies constraints and restrictions to the Dev team Ivory tower? 5

6 Traditional Architecture with an Agile Team Architecture Document Architecture Scrum development 6

7 Agile Architecture Starts with just enough to get going Architectural alternatives are explored up front Key decisions are made during the development iterations Emergent solution architecture evolves as understanding of the system increases during development Incremental using short feedback cycles Offer alternatives, suggestions, and guidance to the Dev team Evolution is the best architect. 7

8 Agile Architecture Continues throughout Dev iterations Add architectural stories that have foundational influence to the backlog Influences the Dev team members Look-ahead prototyping and framework development Unresolved architectural issues or concerns tracked on product backlog 8

9 Agile Architecture Artifacts Diagrams Vision presentations Conceptual models Wikis Brief overview documents Discussions - important findings 9

10 Agile Architecture in Enterprise Scrum 10

11 Agile Architecture in a nutshell 11

12 Agile Architecture 7 principles Principle #1 The teams that code the system designs the system. Principle #2 Build the simplest architecture that can possibly work. Principle #3 When in doubt, code it out. Principle #4 They build it, they test it. Principle #5 The bigger the airplane, the longer the runway. Principle #6 System architecture is a role collaboration. Principle #7 There is no monopoly on innovation. - Dean Leffingwell, - 7 principles of Agile Architecture 12

13 The Agile Architect 13

14 Roles of the Agile Architect Service Provider Alternatives Creator Technical Coach Linchpin 14

15 Service Provider prepare and support Address the requirements (functional, non-functional, quality, reliability, usability, efficiency, maintainability, scalability, portability, consistency, testability, etc.) Work directly with the developers instead of writing documents Develop the required frameworks, demo and show how to use them builds trust! Don t worry so much about breaking the rules, worry more about the system quality 15

16 Service Provider middle ground 16

17 Alternatives Creator A single architectural approach will feel dictated Offer multiple approaches instead Give Dev team guidance on Pros and Cons of each approach Risk What to watch for Hints on what would constitute a decision towards one or another Often times during development, a mesh of the alternatives will emerge as the best overall architecture 17

18 Technical Coach Closely watch (and participate in) the development Offer alternatives, suggestions, and guidance as development progresses Lobby for architectural stories that have foundational significance to the backlog Influence the PO to prioritize these architectural stories high Review the sprint deliverables to insure architectural integrity Track any unresolved architectural issues on product backlog 18

19 Linchpin Bring it all together: Agile and Architecture Sherpa guiding the team to the pinnacle of architecture excellence Ownership of resultant architecture on shipped system 19

20 Nokia Siemens Survey 70% of all architects are satisfied or very satisfied with the impact of Agile development on their work. Survey of over 2,400 developers, testers, architects, and managers K. Vilkki, Impact of Agile Transformation, Flexi Newsletter, vol. 2, no. 1, 2008, pp Reasons: 1. Improved feedback cycles 2. New role closer to actual development AGILE ARCHITECT 20

21 Emergent Architecture 21

22 Emergent Architecture and Design TRADITIONAL Anticipatory AGILE Adaptive Rework Rework Adjust Upfront architecture Evaluate Rework Rework Assess Upfront architecture 22

23 Emergent Architecture and Design If you spend a great deal of time trying to anticipate all the things you'll need before you've started writing code, you will always waste some time because you don't yet know what you don't know. Neal Ford, Evolutionary Architecture and Emergent Design 23

24 Emergent Architecture - technique Up front: identify potential alternatives Knowledge share - Discuss alternatives with Dev team - Draw diagrams - Develop frameworks and prototypes Identify architecturally-significant stories for backlog - Product Owner prioritizes for sprint 0 and/or 1 Iterative development - Team develops, and communicates learnings - Architect guides decisions - Adjust architecture as you go 24

25 Case Study MWave Hardware Monitor Microwave transceivers Several different types Each transceiver made up of VLSI chips Installed on top of buildings Allow hospitals to communicate via WAN Surgeons can pull up patient records anywhere throughout the multi-building complex Requirement: continuous uptime Direction: create a monitoring capability to constantly query and verify the health of the VLSI chip components - Scott L Bain, Emergent Design 25

26 Case Study MWave Hardware Monitor Initial architecture option prior to development sprints Hardware Tier Middle Tier Client Tier Actual Hardware System Drivers VLSI Component pollstatus() pollstatus() Client A Client B VLSI Component pollstatus() Client C <interface> HardwareView VLSI Component Component Manager builds HardwareViewFactory VLSI Component VLSI Component ASCII File Encrypted status Status Monitor VLSI Component 26

27 Case Study MWave Hardware Monitor Sprint 2 identified requirement for complex machines, consisting of boards and sub-boards, each with VLSI chips Actual Hardware System Hardware Tier Middle Tier Client Tier Drivers creates pollstatus() pollstatus() Client A Client B pollstatus() Client C <interface> HardwareView VLSI Chip Sub-Board Board Component Manager builds HardwareViewFactory XML File Encrypted status Status Monitor Component 27

28 Case Study MWave Hardware Monitor Sprint 4 identified requirement for different Encryption mechanisms Actual Hardware System Hardware Tier Middle Tier Client Tier Drivers creates pollstatus() pollstatus() Client A Client B pollstatus() Client C <interface> HardwareView builds Chip Sub-Board Board Component Manager Encrypted status HardwareViewFactory XML File Encryption Status Monitor Component 28

29 Fully Integrated Agile Architecture Approach 29

30 Fully Integrated Agile Architecture Approach Agile Architect responsibilities Scrum Team Diagrams / documents Technical guidance Monitor team progress SERVE the team Evolve architecture based on coding Develop frameworks Verify arch meets requirements Develop prototypes Communicate current arch to business side Help identify PBIs for early sprints Provide feedback Offer architectureimpacting backlog items LISTEN to feedback Break rules correctly Review options with team and business side Initial architectural options Ownership of final architecture Last responsible moment decisions 30

31 Conclusion 31

32 4 Take-aways 1. Agile and Architecture are not at odds 2. Agile Architects are part of the Scrum team - they code and are part of the daily game Agile Architect 3. Agile methods help insure an optimal architecture is achieved 4. Supposed loss of power is more than offset by the trust gained while supporting and guiding the developers! "Architecture is not living in a document - it is living in code, otherwise it would be a beautiful piece of fiction. - Jim Coplien 32

33 References White Papers: Agility and Architecture: Can They Coexist?, Abrahamsson, Babar, and Krutchen, IEEE Software Architects as Service Providers, Roland Faber, IEEE Software Agile-Architecture Interactions, James Madison, IEEE Software Peaceful Coexistence: Agile Developer Perspectives on Software Architecture, IEEE Software Agile Architecture IS Possible You First have to Believe!, IEEE Computer Society 33

34 Questions? Agile Methods training: Scrum Team Training Intro to Agile Distributed Agile Agile Immersion Hemant Elhence, User Stories Requirements w/ Agility Extreme Programming Product Owner Role ScrumMaster Role Etc. All courses can be delivered onsite at your location Short/Long term Agile coaching Facilitated improvement Michael Hall,

35 Synerzip in a Nut-shell 1. Software product development partner for small/midsized technology companies Exclusive focus on small/mid-sized technology companies, typically venture-backed companies in growth phase By definition, all Synerzip work is the IP of its respective clients Deep experience in full SDLC design, dev, QA/testing, deployment 2. Dedicated team of high caliber software professionals for each client Seamlessly extends client s local team, offering full transparency Stable teams with very low turn-over NOT just staff augmentation, but provide full mgmt support 3. Actually reduces risk of development/delivery Experienced team - uses appropriate level of engineering discipline Practices Agile development responsive, yet disciplined 4. Reduces cost dual-shore team, 50% cost advantage 5. Offers long term flexibility allows (facilitates) taking offshore team captive aka BOT option

36 Our Clients

37 Questions? Hemant Elhence

38 THE END Michael Hall Three Beacons