Growing Software Systems

Quick overview of evolutionary software development concepts and processes aimed to grow adaptive systems.

Transcript

1. Software Systems Growing
3. Software systems are grown, not built.
4. Architecture won't gradually emerge out of refactorings.
5. Frameworks are not the architecture Frameworks are TOOLS
6. E-Type Evolution Processes Multi-agent, multi-level, multi-loop feedback systems
7. Categories of Software Systems Conforms to an exact specification. Specification based → mathematical criteria. Consistent with a single external paradigm. Paradigmatic domain → stable assumptions. v.g. Unicode, Physics simulation S-Type P-Type E-Type Actively used and embedded in the real world. Evolutionary systems → constantly adapting to change.
8. A consciously crafted evolutionary baseline architecture allows to: Adapt to change Defer decisions Cope with growth Reduce entropy Nurture quality Evolutionary Architecture Retain conceptual integrity
9. Lehman's Laws of Software Evolution 1. Continuing Change 2. Increasing Complexity 3. Self Regulation 4. Conservation of Organisational Stability 5. Conservation of Familiarity 6. Continuing Growth 7. Declining Quality 8. Feedback System
10. Lehman's Laws of Software Evolution 8. Feedback System 1. Continuing Change 6. Continuing Growth 3. Self Regulation 2. Increasing Complexity 7. Declining Quality 5. Conservation of Familiarity 4. Conservation of Organisational Stability
11. E-Type Evolution Feedback Loops
12. E-Type Planning R1 R2 R3 R4 Priorized Requeriment Queue Anatomy Plan Codebase Stable Baseline N Stable Baseline N+1 Release Captures dependencies & Coordinates parallelism System increments yielding evolution of the codebase IC1 IC2 IC3 IC4
13. SP
14. Software Products Conceptual Network Problem Domain Executable Systems Solves Embodied Essential Complexity Accidental Complexity 9/10 Effort • Tools • Frameworks • Methodologies • Concepts • Collaborations • Algorithms 1/10 Effort
15. Software Product Lines Platform Core Assets Strategic Market Domain Product Family Supports Variants Market Segment Needs Fulfills
16. Evolution of Software Product Models
17. Bibliography Lehman, Meir M. Programs, Life Cycles, and Laws of Software Evolution. Madhavji, Nazim H., Fernandez Ramil Juan Carlos, and Dewayne E. Perry. Software Evolution and Feedback: Theory and Practice. Chichester, England: John Wiley & Sons, 2006. Print. Brooks, Frederick P. The Mythical Man-month: Essays on Software Engineering. Weiss, Michael. Economics of Software Product Development Collectives. Petersen, K. & Wohlin, C. Measuring the Flow in Lean Software Development.
18. References Howeler & Yoon and Squared Design Lab Eco Pods Architectural Design with Robotic Arms. https://www.flickr.com/photos/justinbaeder/ https://www.flickr.com/photos/ellenjo/ https://www.flickr.com/photos/29487767@N02/ https://www.flickr.com/photos/annieominous/
19. Thanks!!!