From Systems to Software
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The document by Tim Sheiner discusses the design of digital machines, emphasizing the importance of system abstraction and the Model-View-Controller (MVC) architecture for achieving modularity, flexibility, and data integrity. It outlines the steps for defining abstractions, creating machine models, and effectively using models to understand machine functions and relationships. Additionally, it highlights the correspondence between digital machines and various models, reinforcing that a comprehensive design incorporates aspects of all models throughout the system.
From Systems to Software
- 1. From Systems to Software The Digital Machine № 2, Design of Digital Machines Tim Sheiner 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States.
- 2. Begin with a definition... 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 2
- 3. A system is an interconnected set of elements that is coherently organized in a way that achieves something. Donella Meadows, Thinking in Systems 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 3
- 4. Make an assumption... 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 4
- 5. These real systems... 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 5
- 6. ...can be abstracted to this form: 1. Objects 2. Relationships A 3. Currency 4. Boundary 5. Purpose Output C Input B D 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 6
- 7. In practice, how is this done? 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 7
- 8. Step 1: define the abstraction 1. Observe the world 2. Learn the terminology 3. Find the currency 4. See relationships 5. Compare to archetypes 6. Play with the puzzle 7. Settle on simple 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 8
- 9. Step 2: abstraction to machine model Machine Model • Conceptual Model Software Machine • Object Model • Interaction Model • Data Model A Output C Input B D 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 9
- 10. The machine has a standard form Controller This is the digital machine. All digital machines are of this form. View Model A Output C Input B D 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 10
- 11. What is the MVC idea? The idea is separation of function. The value is • modularity Controller • flexibility • data integrity View Model 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 11
- 12. What is the MVC idea? The idea is separation of function. The value is • modularity Controller • flexibility • data integrity View Model observer 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 11
- 13. What is the MVC idea? The idea is separation of function. The value is • modularity Controller • flexibility • data integrity View Model observer recorder 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 11
- 14. What is the MVC idea? The idea is separation of function. mediator The value is • modularity Controller • flexibility • data integrity View Model observer recorder 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 11
- 15. MVC is everywhere in digital machines The MVC concept is relevant to the well-designed machine View Controller Model literally, conceptually, tactically, strategically and at every level of Show Do Save analysis. Objects Actions Memory Observer Mediator Recorder Presentation Event Structure Front End Middle Tier Back End Interface Application Database CSS Javascript HTML 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 12
- 16. The MVC Cycle Controller View Model 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 13
- 17. The MVC Cycle Controller request request component state update update report confirm event state change View Model 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 13
- 18. The Design Problem = MVC + User Controller View Model 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 14
- 19. The Design Problem = MVC + User Controller View Model 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 14
- 20. The Design Problem = MVC + User Controller View Model 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 15
- 21. The Design Problem = MVC + User Controller feedback View Model action 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 15
- 22. The Design Problem = MVC + User Controller feedback View Model action We use models to design this system. 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 16
- 23. The models answer these questions 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 17
- 24. The models answer these questions What does the machine do? Conceptual Model Concept How do I change the output? Interaction Model Flow How does it work? Object Model Structure How are the parts related? Data Model Inheritance 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 17
- 25. The models answer these questions What does the machine do? Conceptual Model Concept How do I change the output? Interaction Model Flow How does it work? Object Model Structure How are the parts related? Data Model Inheritance 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 17
- 26. The models answer these questions What does the machine do? Conceptual Model Concept How do I change the output? Interaction Model Flow How does it work? Object Model Structure How are the parts related? Data Model Inheritance 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 17
- 27. The models answer these questions What does the machine do? Conceptual Model Concept How do I change the output? Interaction Model Flow How does it work? Object Model Structure How are the parts related? Data Model Inheritance 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 17
- 28. Correspondence between digital machine and the models object model Input Controller Output View Model Digital Machine interaction model data model conceptual model Each sub model applies most directly to one aspect of the MVC machine. Of course, the well designed machine will have pieces of all the models throughout the entire system. 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 18
- 29. fin 0.5beta 2013 This work by Tim Sheiner is licensed under a Creative Commons Attribution 3.0 United States. 19